You can use background picture-in-picture at any time except when you share content.
1

During a meeting, swipe up from the bottom of the screen to exit the Meetings app.


 

For iOS 13 or 14, tap Background picture-in-picturePicture-in-picture icon and then exit the Meetings app.

2

Open the app that you want to use.


 

Drag the floating window to another location on your screen if it's covering the app you're using. Double tap the window to increase or decrease its size.

3

Tap the floating window to return to the meeting.


 

If you're using iOS 13 or 14, tap the floating window and then tap Background picture-in-picturePicture-in-picture icon to return to the meeting.