Before attempting to troubleshoot any second-factor problem, make sure that the first-factor authentication, your Andrews username and password, is correct.
If this is the first time that you’ve used the Duo service on a particular device, then make sure that the Duo enrollment process
has been completed and then try again. If you’ve used the Duo service on a particular device and cannot log in, then make sure that phone itself is not locked. If the phone is locked, then unlock the phone and start the Duo Mobile app (if on a smartphone) and try again.
Make sure that you’re using the correct mobile device. If you’re using a new device (even if you have the same phone number), then reactivate the Duo Mobile app for the new device. If you’re changing types of phone, such as going from an Android to an iPhone, then select the new type of phone before reactivating. If the service is still not working, contact the ITS Helpdesk
by emailing firstname.lastname@example.org
or calling 269-471-6016.