ipone Unavailable
iPhone 6s, iOS 15
Question marked as
iPhone Unavailable, Security Lockout, or Disabled
You can sometimes remedy this without a computer if on iOS 15.2 or later by tapping on "erase iPhone" , but you will still need the Apple ID password. It will WIPE the phone, no choice!
How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support
video
ios 15.1 and earlier:
If you've forgotten your iPhone passcode – Apple Support (UK)
Find out how the passcode got entered too many times.