https://wccftech.com/this-trick-lets-you-keep-on-playing-youtube-audio-on-ipados-in-the-background/

You can keep on playing YouTube audio in the background even if it is minimized and you’re in another app on iPad running iPadOS.

Here’s how the story goes on the iPad - you are playing something on YouTube, maybe a song or a podcast, you minimize the app and boom, everything goes silent. The way around it? Get YouTube Premium, and it will cost you real money. However, thanks to a little ‘bug’ in iPadOS you can keep on playing YouTube audio in the background if you ditch the official YouTube app and instead opt for Safari.