mobile

Hey guys I was hoping you could help me out. I bought an unlock code for my htc m9 t-mobile variant but It will not let me simply just enter the unlock code. I put an at&t sim card and it took me to this screen (see attachment)

I tried disabling the app, booting in safe mode... nothing works. It doesn't prompt me to enter the unlock code I purchased. It forces me to go through the t-mobile app. Any ideas? Much appreciated!

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