Source: Google
As Google is set to shut down Play Music later this month, the company makes sure those few YouTube Music subscribers on iOS can have access to its service. The YouTube Music app is available on the Apple Watch. It's mostly access to the essentials, turning your Apple Watch into a music remote. But you can do things like browsing your music collection, controlling playback, and "Like" tracks.
There's a complication that adds playback controls to the watch face, but not all watch faces support this feature. It will also let you cast a song from your phone to a speaker and even get recommendations based on your listening habits. It works similar to how Spotify's Apple Watch app works. You'll need at least a Series 3 or above running on watchOS 6 or above to use the app. And yes, you need an active YouTube Premium or YouTube Premium Music subscription, too.
Source: Engadget