Carrie unlock

Your PIN that is set on the device, usually set by the user.  You might be able to bypass it I'm your Google or Apple account but if not.  You might be forced to factory reset the device and then sign in with the Google or Apple account before being able to setup the device again.

Pin not working...says pin required after device starts...this is my only phone...trying to get help using email on my tablet to get help 

T-Mobike USA only SIM unlocks devices for T-Mobile USA customers who meet all of the SIM Unlock Policy requirements.  

https://www.t-mobile.com/responsibility/consumer-info/policies/sim-unlock-policy