Hello! 

I had a student ask for help turning on SMS notifications. She has T-Mobile and is not getting a confirmation code on her phone. Then I tried doing the same and I have Verizon and I also did not get a confirmation code on my phone. We both repeatedly tried deleting and readding the phone numbers. 

In looking for help, I found this article: https://community.canvaslms.com/t5/Canvas-Question-Forum/Why-won-t-my-cell-number-register/m-p/19698... - which, instead of answering the question, says to go to Help >> Report a Problem.

BUT when I do that, I get an error saying "Single Sign-on Error. We can't log you in because of an issue with single sign-on. Contact your Salesforce admin for help." I tried using an incognito window and it still gave me the same error.