app won’t send confirmation code

Very frustrating trying to get the modem to work with XFinity. I am about ready to ship this piece of junk back. Spent hours troubleshooting it and still sketchy set up. 
Right now, trying to use the app and get to the point where it says ‘enter confirmation code’ but the app isn’t sending one. 
It baffles me why the instructions are not better and being many people use XFinity, should be a no brained. Take my money and produce bad products…