All new smartphones that are locked in T-Mobile and Metro Pcs USA network have a new type of network lock called Device unlock app.
Any device that has this type of app, does not ask for a network unlock code.
If you insert an unaccepted simcard in to device from that, the unlock request will be shown in this special app.
There should be two options available displayed in that application, permanent unlock and temporary unlock.
When you press the permanent unlock, the message should say that the device is not eligible for unlocking.
After using this service the device will be unlocked remotely and after than you can use your phone with any network you wish.
The Device unlock APP is available for All Android devices like:
You can make an order to unlock that type of sim-lock on our website:
Unlock device APP for T-Mobile USA
Unlock device APP for MetroPcs