With two-factor authentication, you will protect your account with something you KNOW (your password) and something you HAVE (your Duo-enrolled device).
Once you have enrolled in two-factor authentication, you will log in as usual. Your identity is verified by accepting a push notification from the mobile app, and either entering a passcode sent in a text message or answering a phone call.
No mobile phone? We strongly recommend the mobile app as the most user-friendly option. However, other options are available. Review the Guide to Two-Factor Authentication for further information.