If you don't have access to your Duo Two-Step enrolled device, and only have one device registered, you have two options:

• use a (previously generated) backup code that you saved. Find instructions on how to generate backup codes. You can't enroll a shared phone if someone else already enrolled it in Duo.
• retrieve your device

If users need to set up a new device, they will have to contact the ITS Help Desk for assistance.