My iPhone 12 Pro Max is unavailable

You will need to reset your phone.

If you forgot the passcode on your iPhone, or your iPhone is disabled or unavailable -

Click on the link for instructions on how to reset your passcode without a computer if you have iOS 15.2 or higher.

If you see a iPhone, iPad, or Apple Vision Pro unavailable message or Security Lockout screen - Apple Support

Click on the link for instructions on how to reset your passcode using a computer.

If you forgot your iPhone passcode, use your Mac or PC to reset it - Apple Support

What “password” do you not know?

You need to restore your phone as outlined in the articles linked above.