WebSharingSiteMovie.URL
From Xojo Documentation
Read-Only Property (As String )
The URL of the YouTube video to be displayed. This must be the full URL — the one displayed in the URL field of your browser and NOT the shortened, sharing URLs that YouTube also provides.
Example
This example displays a Xojo webinar in the a WebYouTubeMovie control:
YouTubeMovie1.URL = "https://www.youtube.com/watch?v=XKZf3_lFLZk&list=UUO8PqWKqCmo_Yrmqa82QEDg"