Keyboard

Touch-and-hold the “keyboard” key at bottom-right of the on-screen keyboard; without lifting your finger from the screen, slide your finger to the [Merge &] Dock option - then release.

More information about operation of on-screen keyboards can be found here:

Use the floating keyboard on your iPad – Apple Support

Split and move the keyboard on your iPad – Apple Support

With the software keyboard active, tap and hold thr lower right hand button, a pop-up appears.

Tap Return to Bottom.