Hello guys! Are you still there? :) I'm not sure if I still know how to do it, but I have a short video for you in which I ate vegetable salad with sausage and bread. I wanted to record something for a very long time, but I'm living in a very noisy area right now. Photo is public domain: https://goo.gl/ErP6My (I introduced a change in the image)
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