Open the "My CityU Profile" app.
Open "Set up MFA"
Click "Set up" button next to "Google Authenticator".
Choose the device type
Open the Google Authenticator app on the mobile device, tap the "+" icon, tap "Scan a QR code" and scan the QR code showing on the browser, and click "Next".
You will see a new profile (auth.cityu.edu.hk) showing on the Google Authenticator app
Type the six-digit code showing on the Google Authenticator app to the computer screen, and click "Verify".
The setup is done. You will see "Enabled" next to the Google Authenticator.
Next time when you are asked for MFA, you can choose the Google Authenticator.