Overview
One of the alternate options for Duo authentication for people who don't have a reliable cell phone is the Hardware Token. If your token code isn't working, the most likely reason is it's out of sync.
Detail
Hardware tokens can go out of sync if the button is pressed and the code isn't used. This will sometimes happen with these devices as they rattle around in pockets, purses, and desk drawers. This article from Duo explains the process, and how to fix it (try 3 different codes) - for the purposes of the article our Duo tokens are HOTP devices.
If that fails, you should stop by a Drop-In Support Desk or give the Technology Help Desk a call at 412-624-HELP (4357) so they can verify your account and help get it resynchronized!