Perform a hard reset if your iPhone 12 freezes. This may resolve the software issue that has caused your iPhone to become stuck, allowing you to use it properly once again.
To hard reset your iPhone 12,
press and hold the volume up button for a few seconds, then press and
hold the volume down button. Then hold down the side button until you see the white
Apple logo on your screen. Let the release of the side button once you see the Apple logo. Your iPhone should
restart shortly after that.