Moving between apps in split view or slide over with a bluetooth keyboard

iOS and iPadOS

Hello all. I have a friend, Anastasia, who is using a bluetooth keyboard because she has problems with fine movement and I wonder if there is a way to move between slide over or split view apps. I allready know how to cycle between apps. But I cannot for the life of me find out how I do this. Anastasia can do most of the things on the keyboard. This is why I am looking for keyboard instructions for her. She does talk but can actually use type to siri. There is, I have found, a home button on my keyboard wich Anastasia just needs to hold in. But I cannot figure out how to switch between those apps. She can do a tap though but it would be easier for her if there is a shortcut. Thanks for anny advice.