Open Control Center
If you have an iPad with Face ID, swipe down from the top-right corner
If you have an iPad with a Home button, swipe up from the bottom edge
Tap the Screen Recording button
Wait for the countdown to finish
To record with microphone audio, press and hold the Screen Recording button, then tap Microphone On
To stop recording, open Control Center and tap the Screen Recording button again
Or tap the red status bar or red clock at the top, then tap Stop
Find the recording in the Photos app