Cannot access "canvas.instructure.com" course through mobile app

Hello,

I am an instructor and I set up my Canvas course on my own through Canvas. My course is accessed through a web browser by going to "canvas.instructure.com". I do not use or have a URL that is associated with my institution. Neither myself nor my students are able to use the Canvas mobile app. When we try to log in, it shoots us back to log in at our institution and then tells us we do not have an account. All of the help articles I have read only address using the mobile app with courses that are set up through the institution's "version" of Canvas. Like I said, this is not an institution's version, just one that I set up myself. How can we utilize the mobile app?