Yes. You can setup more than one device for approving Microsoft MFA login. Please follow the steps below.

  1. Firstly, download the Microsoft Authenticator app on your second device.
  2. Open a browser on your computer and sign in to GTIIT webmail - 
  3. Sign in to Office 365 with your GTIIT email address as username and your password.
  4. Verify your identity via the Authenticator app on your primary device.
  5. Once logged in, click your profile icon on upper right. Then choose "View account".
  6. From the left panel, choose "Security info". Then choose "+ Add method" on the right hand side.
  7. From the "Which method would you like to add?", Choose "Authenticator app" and click "Add".
    Choose to use Authenticator app
  8. It will remind you to download the "Microsoft Authenticator app" for your mobile device. If you have done so, click "Next". (If you don't have the app yet, download it from the store on your device (Android | iOS | Windows Phone)
    Authenticator app
  9. Click "Next" to proceed.
    Authenticator app record
  10. When you see the following screen, open the Microsoft Authenticator app on your device. Authenticator app icon.MFA configure with QR code
  11. Click “+” to add an account and choose “Work or school account”.
    Add account on Authenticator appAdd account on Authenticator app
  12. Scan the QR code on the computer. (Notes: iPhone users may have to enable the camera in Settings in order to scan.)
  13. If you can't use your phone camera, you'll have to manually enter the 9 digit code and the URL.
  14. You will be shown a six-digit code and your account is added.
  15. Switch back to your computer and click "Next".
    MFA configure with QR code
  16. The system will send a notification to your device.
    Authenticator app icon
  17. You will then receive a notification on your device.
    Authenticator app icon
  18. Click “Approve” on the app as the second step of verification.
  19. When the "Notification Approved" message shown, click "Next".
    Notification Approved
  20. Then a new entry will be shown with your device name.
    List of registered devices
  21. You're good to go!
  22. From now on, all your devices registered with the Microsoft Authenticator app will notify you to verify the sign-in. You only need to response it (Approval or Deny) on one of the devices.