diff --git a/activitypub-event-transformers.php b/activitypub-event-transformers.php
index 1f6f2bd..501dec5 100644
--- a/activitypub-event-transformers.php
+++ b/activitypub-event-transformers.php
@@ -25,7 +25,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 add_filter(
 	'activitypub_transformer',
 	function( $transformer, $wp_object, $object_class ) {
-		if ( 'WP_Post' != $object_class) {
+		if ( 'WP_Post' != $object_class ) {
 			return $transformer;
 		}
 
@@ -33,67 +33,30 @@ add_filter(
 		 * VS Event List
 		 * @see https://wordpress.org/plugins/very-simple-event-list/
 		 */
-		// if ( $wp_object->post_type === 'event' ) {
-		// 	require_once __DIR__ . '/includes/activitypub/transformer/class-vs-event.php';
-		// 	return new \VS_Event( $object );
-		// }
+		if ( class_exists( 'vsel_widget' ) && $wp_object->post_type === 'event' ) {
+			require_once __DIR__ . '/includes/activitypub/transformer/class-vs-event.php';
+			return new \VS_Event( $object );
+		}
 
 		/**
 		 * Events manager
 		 * @see https://wordpress.org/plugins/events-manager/
 		 */
-		if ( class_exists( 'EM_Events') && $wp_object->post_type === 'event' ) {
+		if ( class_exists( 'EM_Events' ) && $wp_object->post_type === 'event' ) {
 			require_once __DIR__ . '/includes/activitypub/transformer/class-events-manager.php';
 			return new \Events_Manager( $wp_object );
 		}
 
 		// Return the default transformer.
+
 		return $transformer;
 	},
 	10,
 	3
 );
 
-/**
- * Add admin notices for improved usability.
- */
-function check_some_other_plugin() {
-	if ( is_plugin_active( 'activitypub/activitypub.php' ) ) {
-		if ( is_plugin_active( 'very-simple-event-list/vsel.php' ) ) {
-			add_action( 'admin_notices', 'vsel_admin_notices' );
-		}
-	}
-}
-
-add_action( 'admin_init', 'check_some_other_plugin' );
-
-function vsel_admin_notices() {
-	$is_vsel_edit_page = isset( $_GET['post_type'] ) && $_GET['post_type'] === 'event';
-	$is_vsel_settings_page = strpos( $_SERVER['REQUEST_URI'], '/wp-admin/options-general.php?page=vsel' ) !== false;
-	$is_vsel_page = $is_vsel_edit_page || $is_vsel_settings_page;
-	$vsel_post_type_is_activitypub_enabeld = in_array( 'event', get_option( 'activitypub_support_post_types' ) );
-	if ( $is_vsel_page && ! $vsel_post_type_is_activitypub_enabeld ) {
-		$vsel_plugin_data = get_plugin_data( WP_PLUGIN_DIR . '/very-simple-event-list/vsel.php' );
-		$activitypub_plugin_data = get_plugin_data( WP_PLUGIN_DIR . '/activitypub/activitypub.php' );
-		$notice = sprintf(
-			_x(
-				'You have installed the %1$s plugin, but the event post type of %2$s is not enabled in the <a href="%3$s">%1$s settings</a>.',
-				'admin notice',
-				'your-text-domain'
-			),
-			$activitypub_plugin_data['Name'],
-			$vsel_plugin_data['Name'],
-			admin_url( 'options-general.php?page=activitypub&tab=settings' )
-		);
-		wp_admin_notice(
-			$notice,
-			array(
-				'type' => 'warning',
-				'dismissible' => true,
-			)
-		);
-	}
-}
+require_once __DIR__ . '/admin/class-admin-notices.php';
+new \Admin_Notices();
 
 /**
  * Add a filter for http_request_host_is_external
diff --git a/admin/class-admin-notices.php b/admin/class-admin-notices.php
new file mode 100644
index 0000000..c96410a
--- /dev/null
+++ b/admin/class-admin-notices.php
@@ -0,0 +1,84 @@
+<?php
+/**
+ * ActivityPub Transformer for the plugin Very Simple Event List.
+ *
+ * @package activity-event-transformers
+ * @license AGPL-3.0-or-later
+ */
+
+class Admin_Notices {
+	const VSEL_PLUGIN_FILE = 'very-simple-event-list/vsel.php';
+	const VSEL_POST_TYPE = 'event';
+	const EVENT_MANAGER_PLUGIN_FILE = 'events-manager/events-manager.php';
+	const EVENT_MANAGER_POTS_TYPE = 'event';
+	const ACTIVITYPUB_PLUGIN_FILE = 'activitypub/activitypub.php';
+
+	/**
+	 * Add actions and filters.
+	 */
+	public function __construct() {
+		add_action( 'admin_init', array( self::class, 'check_for_admin_notices' ) );
+	}
+
+	/**
+	 * Check the conditions for admin notices
+	 *
+	 * These should mainly improve usability.
+	 */
+	public static function check_for_admin_notices() {
+
+		if ( is_admin() && is_plugin_active( self::ACTIVITYPUB_PLUGIN_FILE ) ) {
+			// Check for VSEL
+			if ( is_plugin_active( self::VSEL_PLUGIN_FILE ) && self::post_type_is_not_activitypub_enabled( self::VSEL_POST_TYPE ) ) {
+				add_action( 'admin_notices', array( self::class, 'vsel_admin_notices' ) );
+			}
+		}
+	}
+
+	/**
+	 * Check if ActivityPub is enabled for the custom post type of the event plugin.
+	 *
+	 * @param string $post_type The post type of the event plugin.
+	 * @return bool
+	 */
+	private static function post_type_is_not_activitypub_enabled( $post_type ) {
+		return ! in_array( $post_type, get_option( 'activitypub_support_post_types' ) );
+	}
+
+	/**
+	 * Check whether to do any admin notices for VSEL
+	 */
+	public static function vsel_admin_notices() {
+		$is_vsel_edit_page = isset( $_GET['post_type'] ) && $_GET['post_type'] === 'event';
+		$is_vsel_settings_page = strpos( $_SERVER['REQUEST_URI'], '/wp-admin/options-general.php?page=vsel' ) !== false;
+		$is_vsel_page = $is_vsel_edit_page || $is_vsel_settings_page;
+		if ( $is_vsel_page ) {
+			self::do_admin_notice_post_type_not_activitypub_enabled( self::VSEL_PLUGIN_FILE );
+		}
+	}
+
+	/**
+	 * Print admin notice that the current post type is not enabled in the ActivityPub plugin.
+	 */
+	private static function do_admin_notice_post_type_not_activitypub_enabled( $event_plugin_file ) {
+		$vsel_plugin_data = get_plugin_data( WP_PLUGIN_DIR . '/' . $event_plugin_file );
+		$activitypub_plugin_data = get_plugin_data( WP_PLUGIN_DIR . '/' . self::ACTIVITYPUB_PLUGIN_FILE );
+		$notice = sprintf(
+			_x(
+				'You have installed the %1$s plugin, but the event post type of %2$s is not enabled in the <a href="%3$s">%1$s settings</a>.',
+				'admin notice',
+				'your-text-domain'
+			),
+			$activitypub_plugin_data['Name'],
+			$vsel_plugin_data['Name'],
+			admin_url( 'options-general.php?page=activitypub&tab=settings' )
+		);
+		wp_admin_notice(
+			$notice,
+			array(
+				'type' => 'warning',
+				'dismissible' => true,
+			)
+		);
+	}
+}
diff --git a/includes/activitypub/handler/class-join.php b/includes/activitypub/handler/class-join.php
new file mode 100644
index 0000000..e69de29
diff --git a/includes/activitypub/transformer/class-events-manager.php b/includes/activitypub/transformer/class-events-manager.php
index 981cf3e..774185a 100644
--- a/includes/activitypub/transformer/class-events-manager.php
+++ b/includes/activitypub/transformer/class-events-manager.php
@@ -22,7 +22,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 
 /**
  * ActivityPub Transformer for events from the WordPress plugin 'Events Manager'
- * 
+ *
  * @see https://wordpress.org/plugins/events-manager/
  *
  * @since 1.0.0
@@ -30,7 +30,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 class Events_Manager extends Post {
 	/**
 	 * Holds the EM_Event object.
-	 * 
+	 *
 	 * @var EM_Event
 	 */
 	protected $em_event;
@@ -85,6 +85,10 @@ class Events_Manager extends Post {
 		return 'Event';
 	}
 
+	protected function get_is_online() {
+		return 'url' === $this->em_event->event_location_type;
+	}
+
 	/**
 	 * Get the event location.
 	 *
@@ -92,20 +96,34 @@ class Events_Manager extends Post {
 	 * @return array The Place.
 	 */
 	public function get_location() {
+		if ( 'url' === $this->em_event->event_location_type ) {
+			return null;
+		}
+
 		$location = new Place();
 		$em_location = $this->em_event->get_location();
 
 		$location->set_name( $em_location->location_name );
-		$location->set_address( array(
+
+		$address = array(
 			'type' => 'PostalAddress',
 			'addressCountry' => $em_location->location_country,
 			'addressLocality' => $em_location->location_town,
 			'streetAddress' => $em_location->location_address,
 			'name' => $em_location->location_name,
-		));
+		);
+		if ( $em_location->location_state ) {
+			$address['addressRegion'] = $em_location->location_state;
+		}
+		if ( $em_location->location_postcode ) {
+			$address['postalCode'] = $em_location->location_postcode;
+		}
+
+		$location->set_address( $address );
 		return $location;
 	}
 
+
 	/**
 	 * Get the end time from the events metadata.
 	 */
@@ -122,13 +140,13 @@ class Events_Manager extends Post {
 		$timezone_string = $this->em_event->event_timezone;
 
 		// Create a DateTime object with the given date, time, and timezone
-		$datetime = new DateTime($date_string . ' ' . $time_string, new DateTimeZone($timezone_string));
+		$datetime = new DateTime( $date_string . ' ' . $time_string, new DateTimeZone( $timezone_string ) );
 
 		// Set the timezone for proper formatting
-		$datetime->setTimezone(new DateTimeZone('UTC'));
+		$datetime->setTimezone( new DateTimeZone( 'UTC' ) );
 
 		// Format the DateTime object as 'Y-m-d\TH:i:s\Z'
-		$formatted_date = $datetime->format('Y-m-d\TH:i:s\Z');
+		$formatted_date = $datetime->format( 'Y-m-d\TH:i:s\Z' );
 		return $formatted_date;
 	}
 
@@ -149,7 +167,7 @@ class Events_Manager extends Post {
 		$em_bookings = $this->em_event->get_bookings()->get_bookings();
 		return count( $em_bookings->bookings );
 	}
-	 
+
 	protected function get_content() {
 		return $this->wp_object->post_content;
 	}
@@ -168,16 +186,40 @@ class Events_Manager extends Post {
 		return $summary;
 	}
 
+	// protected function get_join_mode() {
+	//  return 'free';
+	// }
+
+	private function get_event_link_attachment() {
+		$event_link_url = $this->em_event->event_location->data['url'];
+		$event_link_text = $this->em_event->event_location->data['text'];
+		return array(
+			'type' => 'Link',
+			'name' => 'Website',
+			// 'name' => $event_link_text,
+			'href' => \esc_url( $event_link_url ),
+			'mediaType' => 'text/html',
+		);
+	}
+
 	/**
 	 * Overrides/extends the get_attachments function to also add the event Link.
 	 */
 	protected function get_attachment() {
+		// Get attachments via parent function
 		$attachments = parent::get_attachment();
+
+		// The first attachment is the featured image, make sure it is compatible with Mobilizon.
 		if ( count( $attachments ) ) {
 			$attachments[0]['type'] = 'Document';
 			$attachments[0]['name'] = 'Banner';
 		}
 
+		if ( 'url' === $this->em_event->event_location_type ) {
+			$attachments[] = $this->get_event_link_attachment();
+		}
+		return $attachments;
+
 		return $attachments;
 	}
 
@@ -258,11 +300,13 @@ class Events_Manager extends Post {
 	 * @return Activitypub\Activity\Event
 	 */
 	public function to_object() {
-		$this->em_event = new EM_Event( $this->wp_object->ID, 'post_id');
+		$this->em_event = new EM_Event( $this->wp_object->ID, 'post_id' );
 		$activtiypub_object = new Event();
 
 		$activtiypub_object = $this->transform_object_properties( $activtiypub_object );
 
+		$activtiypub_object->set_external_participation_url( $this->get_url() );
+
 		return $activtiypub_object;
 	}
 }
diff --git a/includes/activitypub/transformer/class-tribe.php b/includes/activitypub/transformer/class-tribe.php
index 270201f..16e38c1 100644
--- a/includes/activitypub/transformer/class-tribe.php
+++ b/includes/activitypub/transformer/class-tribe.php
@@ -152,21 +152,21 @@ class Tribe extends Post {
 	 */
 	public function get_event_location() {
 		/*
-			   'post_title' => 'testvenue',
-			   'post_name' => 'testvenue',
-			   'guid' => 'http://localhost/venue/testvenue/',
-			   'post_type' => 'tribe_venue',
-			   'address' => 'testaddr',
-			   'country' => 'Austria',
-			   'city' => 'testcity',
-			   'state_province' => 'testprovince',
-			   'state' => '',
-			   'province' => 'testprovince',
-			   'zip' => '8000',
-			   'phone' => '+4312343',
-			   'permalink' => 'http://localhost/venue/testvenue/',
-			   'directions_link' => 'https://maps.google.com/maps?f=q&#038;source=s_q&#038;hl=en&#038;geocode=&#038;q=testaddr+testcity+testprovince+8000+Austria',
-			   'website' => 'https://test.at',
+				'post_title' => 'testvenue',
+				'post_name' => 'testvenue',
+				'guid' => 'http://localhost/venue/testvenue/',
+				'post_type' => 'tribe_venue',
+				'address' => 'testaddr',
+				'country' => 'Austria',
+				'city' => 'testcity',
+				'state_province' => 'testprovince',
+				'state' => '',
+				'province' => 'testprovince',
+				'zip' => '8000',
+				'phone' => '+4312343',
+				'permalink' => 'http://localhost/venue/testvenue/',
+				'directions_link' => 'https://maps.google.com/maps?f=q&#038;source=s_q&#038;hl=en&#038;geocode=&#038;q=testaddr+testcity+testprovince+8000+Austria',
+				'website' => 'https://test.at',
 		 */
 		$venue = $this->tribe_event->venues[0];
 		return ( new Place() )
@@ -174,8 +174,8 @@ class Tribe extends Post {
 			->set_name( $venue->post_name )
 			->set_address(
 				$venue->address . "\n" .
-						   $venue->zip . ', ' . $venue->city . "\n" .
-						   $venue->country
+							$venue->zip . ', ' . $venue->city . "\n" .
+							$venue->country
 			); // todo add checks that everything exists here (lol)
 	}
 }
diff --git a/includes/activitypub/transformer/class-vs-event.php b/includes/activitypub/transformer/class-vs-event.php
index 9e9266e..9cef4f1 100644
--- a/includes/activitypub/transformer/class-vs-event.php
+++ b/includes/activitypub/transformer/class-vs-event.php
@@ -206,7 +206,7 @@ class VS_Event extends Post {
 	public function get_summary() {
 		if ( $this->wp_object->excerpt ) {
 			$excerpt = $this->wp_object->post_excerpt;
-		} else if ( get_post_meta( $this->wp_object->ID, 'event-summary', true ) ) {
+		} elseif ( get_post_meta( $this->wp_object->ID, 'event-summary', true ) ) {
 			$excerpt = get_post_meta( $this->wp_object->ID, 'event-summary', true );
 		} else {
 			$excerpt = $this->get_content();