Once you have scanned the QR code the presented ID number within your chosen authenticator app will refresh every 30 seconds.
If when you enter your code you receive the above please remain on your authenticator app and try the next available code that is presented.
If this does not resolve your issue you may need to check that your authenticator app is in-sync with the official time.
If your phone's time is out of sync or if you have changed time zones, the best way to fix is to change the time settings on your phone from 'Manual' to 'Automatic'. If already set to 'Automatic' toggle it off and on to re-sync the app.
Should problems persist thereafter please submit a request with your details so we can investigate further.