The audio of me putting on my makeup (but i don't do this everyday!)... sorry that it is just the audio, but the video part got messed up! (This is an old video! I don't have a new camera yet!)
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