My iPhone is unavailable, unable to unlock my iPhone
iPhone unavailable I can’t unlock my phone
[Re-Titled by Moderator]
iPhone 12 Pro Max
Question marked as
If you forgot a passcode that you changed within the last 72 hours, see the "If you recently changed passcodes, use your old passcode to temporarily sign in" section of: If you see a iPhone, iPad, or Apple Vision Pro unavailable message or Security Lockout screen - Apple Support
Otherwise, see the other sections of that article
If neither of the above is an option, you will need to use a computer. See: If you forgot your iPhone passcode, use your Mac or PC to reset it - Apple Support