unlocked iphone 11 pro or Not

The only way to purchase an unlocked phone from Apple is to

select the "Unlocked and SIM free" option. If you selected any

of the carriers, regardless of whether you paid full price or not,

it is locked to that carrier and you will need to follow that carriers

procedures to unlock the phone as only they can do it.

You bought a locked phone from AT&T. You would need to contact AT&T to have them unlock it then you restore it as new.

Or return the device and buy it carrier unlock if Apple offers it.

FWIW, unlocking a phone from a carrier will disable some carrier services

that a carrier locked phone would have, WiFi calling typically being

one of those services.