Home Internet, stuck on setup menu but it is working

My T-Mobile Home Internet is working, but I want to make a change.   I use a PC and Ethernet connection.  Whenever I go into the admin menu, I get the new setup menu and not the normal admin one with all the settings.   I try to go through the setup, but it gets stuck at the point when I have to scan the QR on the device, it keeps failing.  Then it wants me to do the Ethernet setup using the app on the phone.  That doesn't even make sense, how can I connect my phone to an Ethernet port and how can I use the app on my PC when they don't make an app for the PC.  (no one on their phone tech line even understands the basics of networking or telephony.)

Once again, T-Mobile has be stuck.

Steve