To add a second device in Duo you will need to open an application that requires a Duo login(GullNet/MyClasses/etc).
After entering your user name and password you will be prompted for Duo verification.
At the Duo Authentication screen select Add a new Device
You will be prompted to authenticate. Choose Send Me a Push or Enter a Passcode and complete the authentication to login.
Once authenticated it will ask what type of device you would like to add-make the appropriate selection.
You will then be asked what type of operating system is on the device
You will need to have Duo installed on the second device. If you have not already done so please do that now.
Once you click I have Duo Mobile Installed a QR code will show on screen.
Go to the new device and open the Duo app. Press the + button to scan the code.
You will receive a green check mark on screen once your device is successfully activated.
Press Continue to complete the login and setup process.