A forgotten or unknown iPhone/iPad passcode cannot be recovered - and neither can it be reset or modified from another device. If you see a waiting period you can wait and try again to input the correct Passcode; otherwise, the iPad must be restored.
You may find this support page to be helpful:
If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support
iOS/iPadOS 15.2 or later with a forgotten Passcode
Apple has introduced a procedure with which to reset an iPad or iPhone with a forgotten Passcode - allowing you to use your AppleID and associated Password to reset your device.
How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support
You will be able to restore data from a pre-existing iCloud backup without the use of a computer, but will require a PC/Mac to restore data from an iTunes backup.
iPadOS 15.1 and earlier - and all devices that are Disabled
If your iPhone/iPad indicates that it is disabled/unavailable/locked-out, or you have forgotten your iPad passcode, you have no alternative other than to follow this process:
If you’ve forgotten the passcode on your iPad, or your iPad is disabled – Apple Support
You’ll need access to either a Windows PC (with iTunes for Windows installed) or a Mac (with iTunes or Finder - as appropriate for the installed version of macOS).
Download and use iTunes for Windows – Apple Support
Update to the latest version of iTunes – Apple Support
If you iPad is not recognised when connected to your computer, try using a different USB port; if your computer has both USB-C and USB Type-A ports, try using the USB Type-A port of the computer.
If difficulties persist, this support page may help with troubleshooting:
If your computer doesn't recognize your iPhone or iPad - Apple Support
Use of a PC or Mac is unavoidable. If you don’t have access to a suitable computer of your own, that of a helpful friend or family member will suffice. Alternatively, the technicians at the Genius Bar of your local Apple Store will be delighted to assist:
Genius Bar Reservation and Apple Support Options - Apple
AppleID
You may also need your AppleID and associated password. If these have also been forgotten, they can be recovered here:
https://iforgot.apple.com
To recover your credentials, you’ll need access to one of the following:
- Your primary email address mailbox that corresponds with your AppleID
- Any of the secondary/recovery email addresses that should be configured for your AppleID account
- Any of the trusted telephone numbers (fixed line or Cellular/Mobile) that are associated with your AppleID
More information about recovery of your AppleID and associated Password:
If you forgot your Apple ID - Apple Support
If you forgot your Apple ID password - Apple Support
If you remain unable to resolve the problem, you would be well advised to visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to assist:
Genius Bar Reservation and Apple Support Options - Apple
