How do I watch YouTube in Picture-in-Picture on iPhone?

As it currently stands (iOS 14 public beta), the YouTube app does not appear to work with the new Picture in Picture feature. There is a workaround however - you can go to YouTube in a browser (Safari, Chrome, Firefox etc.), play a video in full screen mode, then just tap the Picture in Picture button (if you don't see it just tap the screen and a bunch of control buttons will appear). Once you have the PIP on your screen you can drag it to any corner and you can tap on it to see rewind/fast forward and close buttons.