I am currently using the media_extractor service. I have confirmed that Live Twitch videos and standard Youtube videos work with no issues. This is my service data:
entity_id: media_player.living_room_tv
media_content_id: 'https://www.youtube.com/watch?v=hHW1oY26kxQ'
media_content_type: 'video'
I’ve also tried ‘video/youtube’ and that doesn’t work either. The chromecast attempts to connect to the url but fails.