how to disable a iPhone 11

Why do you want to disable your phone?

If the phone days it is already disabled and you want to enable it then you can use a  computer and the Apple ID password, but unfortunately it will wipe the phone

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

In iOS 15.2 passcode Locked phones can be erased without a computer. You need the AppleID password.  It will wipe the phone. 

https://support.apple.com/en-us/HT212951