The unlock is permanent (relock warrantly).
Unlocking consists of assigning IMEI to the Apple database.
The iPhone will be permanently unlocked, and after the software update, the lock will not come back.

All software versions are supported.

Supported Models:

iPhone  Xr/Xs/Xs Max/11/11 Pro

Permanent iPhone unlocking running on the Sprint network.
Please insert an unaccepted simcard and turn on WI-FI, the iPhone will be unlocked remotely.