Won't send verification code when trying to set up Chevy app

I got OnStar and most of the Chevy app set up but it's requiring me to add a two verification code that is sent either through text message or email. The problem is it keeps telling me that it is unable to send or there was an error. I have deleted and re-downloaded the app I have logged out and logged back in many times and it continuously says the same thing. I have even restarted my phone. How can I get past this so I can use the app