“floating/onscreen keyboard” on iPad Pro with magic keyboard

I have an iPad Pro with a Magic Keyboard attached which I always use. The onscreen keyboard has suddenly appeared and now I can’t use the Magic Keyboard, which is very annoying. I assume I must have accidentally “hit” a button on the Magic keyboard to make this happen! Can anyone tell me how to get rid of the on screen keyboard so I can go back to typing from the Magic Keyboard.