Apple Support Document: https://support.apple.com/guide/ipad/restart-ipad-ipad63d30b5a/ipados
Turn iPad off and on
To turn off iPad, do one of the following:
On an iPad with a Home button: Press and hold the top button until the slider appears, then drag the slider.
On an iPad with Face ID: Simultaneously press and hold the top button and either volume button until the sliders appear, then drag the top slider.
All models: Go to Settings > General > Shut Down, then drag the slider.
To turn iPad back on, press and hold the top button until the Apple logo appears.
Force restart iPad
If iPad isn’t responding, do one of the following:
On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.
Note: If iPad still doesn’t turn on, or if it gets stuck during start up, see the Apple Support article If your iPhone, iPad, or iPod touch won’t turn on or is frozen.