I do not recommend doing this as the fibers are glass and can break off, but I did it anyway. This lamp was actually my grandma's and she gave it to me because as a child I used to watch it for hours when I stayed over at her house. It always relaxed me at night time.
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