If you enter the wrong passcode too many times, you’ll see a message that your iPad is disabled. If you can’t remember your passcode, you need to erase your iPad, which deletes your data and settings, including the passcode.
If you backed up your iPad, you can restore your data and settings after restoring your iPad. If you never backed up your iPad before you forgot your passcode, you won't be able to save the data on your iPad. Follow the steps below to remove your passcode.
Support Article: If you forgot the passcode on your iPad, or your iPad is disabled - Apple Support