Sign into a Duo protected service, such as "MyAccount".
Click "Other options" at the bottom of the Duo prompt.
Choose "Manage devices" at the bottom of the Duo prompt.
Select "Text message passcode" to receive an SMS text with one sign in code.
Enter the SMS passcode and click "Verify"
If successful, you will get a "You're verified" screen.
Choose whether you are replacing your old phone with "I have a new phone" or "Add a device" to add additional devices to log into your account with.
For more information, visit the Frequently Asked Questions (FAQ) page.