Unlock iPhone from Tmobile Carrier

Dear Apple Community,

I paid off my iPhone SE and 7 from Tmobile and want to unlock them.

The message the carrier has sent states I have to 2 options (one with an alt sim) and with tMobile still as my carrier the second~which requires I back the bloody phone up and erase the phone.

Is this necessary?

Are their any other options or is this another carrier type push (see my post on apple watches thru carriers that you all helped me with).

Thank you in advance, and if its you Phil, you rock. Anyone who helps, of course but Phil you are really helpful to the community and I have learned much from all your efforts.

Best~