How to put your iPhone or iPad in DFU mode to fix it as a last resort

DFU mode can help you recover your iPhone or iPad using a computer.
Yahoo

Using iPad Recovery Mode to Fix a Frozen or Unresponsive Device

Recovery Mode: Connect iPad to a computer > open Finder (Catalina or later) or iTunes > restart > Update from the recovery screen. If you don't have access to a computer, use iCloud to wipe the iPad ...

How To Hard Reset An iPad (Any Model) - And Why You Might Want To

Is your iPad not responding, not powering on, or just generally being a nuisance? Sometimes a hard reset is necessary, and it's very easy to perform.

How to change or reset your iPad's passcode, even if you don't remember what the passcode is

To reset or change your iPad's passcode, you can use the "Passcode" menu in your Settings app, or reset the entire device.
Gizmodo

How to Reset an iPad Without a Password

Forgetting your iPad passcode can be a hassle. You could easily get locked out of it because there’s also a limit to how many times you can enter a different four- and six-digit combo. Once you hit ...