If you have made several tries with the MFA and still not working:
For Android:
- Go to the Google Authenticator app on your phone
- Click on the 3 dots located at the top right of the screen
- Click on Configuration
- Click on Time Correction for codes
- Click on Sync Now
For Iphone:
- Go to the Iphone Settings
- Select General
- Select Date & Time
- Enable Set Automatically
After that please try again to add it on your Revmax login.