Press and hold the side button and either volume button until the power off slider appears
Drag the slider to turn off your iPhone
Wait about 30 seconds
Press and hold the side button again until the Apple logo appears
If your iPhone has a Home button, press and hold the side button or top button until the power off slider appears
Drag the slider to turn off your iPhone
Wait about 30 seconds
Press and hold the side button or top button again until the Apple logo appears
If your iPhone is frozen, quickly press and release the volume up button
Quickly press and release the volume down button
Press and hold the side button until the Apple logo appears