How do I connect a Netgear Nighthawk wifi range extender to the T-Mobile internet gateway

I took me about 5 minutes to complete setting up. First press hard reset button, then search and connect to your Netgear extension wifi. They will ask you what netwwork you would like to connect to from the list, select T mobile. Will ask passcode, then if you want to use the same passcode for the extension.

Thanks for some instructions before about the hard reset and using mobile device.