NOTE: I apologize for the blurry video. Yes, I know it's blurry. I'm still working on that. We'll take a look at several rings I have recently purchased at Wish and from Toys & Co. (seriously!), as well as a nifty watch!
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app