Open Settings
Tap Control Center
Add Screen Recording to Control Center if it is not already included
Swipe down from the top-right corner of the screen on iPhone with Face ID
Swipe up from the bottom edge on iPhone with a Home button
Tap the Screen Recording button
Wait for the three-second countdown
Record your screen
To stop recording, tap the red status bar or red clock at the top of the screen
Tap Stop when prompted
Find the recording in the Photos app