Payed for has nothing to do with it being unavailable, an incorrect password was entered too many times and the phone went into lock down mode.
Did you just purchase this phone from someone and it came locked? If so, try to get your money back, you most likely purchased a stolen phone and you will never get it to work.
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 or your iPhone is disabled - Apple Support