How to disable touch on your iPad, iPhone
Go to Settings - General - Accessibility - Guided Access.
Turn on Guided Access.
Tap Passcode Settings, then tap Set Guided Access Passcode.
Enter a passcode, then reenter it. From here, you can also turn on Face ID or Touch ID as a way to end a Guided Access session.
Start a Guided Access session
Open the app that you want, then triple-click the Home button. For iPhone X, triple-click the side button.
If you want parts of your screen to stop responding to touch, use one finger to circle those areas. You can move or resize the circle, or tap the X to remove it.
Tap Start.
Or to start a Guided Access session with Siri*, open the app that you want, then tell Siri "Turn on Guided Access."
Control which features are available
To turn off features or set a time limit, triple-click the Home or side button, then tap Options. If you don't see Options, triple-click the Home or side button again and enter your passcode.
Turn on the options that you want, then tap Done.