Hello @KellyVikstrom-H ...
When I go to my own "Account" >> "Settings" screen in Canvas, under the "Other Contacts" area, there is an area to "+ Contact Method". When the small new window opens, there is a "Text (SMS)" tab...which I think you are referring to. However, there is a note on that tab that says, "SMS is only used for Multi-Factor Authentication (if enabled for your account)." I'm not sure if the student was hoping to get text message notifications about her course(s), but this is no longer an option.
How do I add a text (SMS) contact method in Canvas... - Instructure Community (canvaslms.com)
It used to be that you could get course notifications as text messages, but not so much any more. You can still choose to get e-mail notifications and push notifications through the Canvas apps on your mobile device, though.
Hope this helps.