When two-factor authentication is enabled for the organization. with the authenticator app, the learners will be prompted to configure it any one of the authenticator apps - Microsoft authenticator app, Google authenticator app, authy, etc. 

 To configure: 

1. The learner uses login credentials (mail ID & password to log in)
2. Then the learner is asked to enter the OTP via mail, and when entered
3. The learner is asked to configure: 
   
   
   
   
   
   
4. Now upon configuration as mentioned in the above image, the learner is asked to enter the OTP from the authenticator app to log in: 
   
   
5. Upon successful entry of the OTP, the learner is asked to download/copy the backup codes issued by the system. These can be used in case the learner loses access to the authenticator app or does not receive OTP from the authenticator app. If the fallback option to receive OTP via mail is enabled by admins, then the same can also be used to log in.
   
   
6. After downloading the backup codes or copying them, the learner is allowed to log in. In case of failure of configuration the learner will be asked to reconfigure.
7. The learner can also reconfigure the same by going to Profile > Settings > Account Credentials > Two Factor Authentication and repeating the above steps.

When the learner loses access to the authenticator's OTP, the learner can use the backup code to log in.

However, this is only a temporary measure as the backup codes expire for every login and the latest one has to be entered for every new login. Now, considering the fact backup codes are limited it is better to reconfigure 2FA. 

As soon a learner uses backup code to log in, they will be prompted to reconfigure 2FA.