My iPhone is blocked with “iPhone Unavailable” message

It's not a phishing scam, the password on your phone was entered incorrectly too many times and for security purposes, the phone locks itself.

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.

How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support

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

If you forgot your iPhone passcode - Apple Support

Not a scam. The phone is "Unavailable" because you....or someone else.....entered the wrong passcode too many times. So, it might be a good idea to first try to understand why this happened.....so it can be avoided in the future.