There are situations where you may need to use a secondary login method for Duo two-factor authentication. A secondary login method would be any additional method to authenticate through Duo using something other than what you have set as your default method.
To use a secondary login method, you must first have more than one device enrolled in Duo. See Decide What Device to Enroll in Duo to find out ways to enroll multiple devices.
Using a Secondary Login Method
Go to the application that you need to login into.
If prompted, enter your internet ID and password and click Sign In.
On the Duo authentication page, click the arrows in the Device box to open up a drop-down menu showing all devices you have enrolled in Duo.
Select the device you want to use to authenticate.
Click the the method of authentication you want to receive on that device.
Wait for the authentication method to be received on your device and proceed as directed.