There is a collection of self-service resources available here: https://www.acns.colostate.edu/duo/ which pertain to setting up and troubleshooting DUO. If you're still having issues after following the step-by-step guide for registering your first device then the next best step is to reach out to Central IT support. Their hours of availability and contact information are listed on the page linked above.

If after trying to follow the self-service guides and reaching out to Central IT for support you're still having issues, then please email oee_helpdesk@colostate.edu and we'll see what we can do to offer additional assistance.