You can create, enable, or disable backup codes in the domain settings after successfully logging in for the first time. This option is only available when 2FA is setup and is only applicable when one-time passwords are enabled. The backup code is designed as a fail-safe option in the event the user misplaces the 2FA device / token or when they are unable to receive it because of their location. Examples would be while in flight where SMS messages might not function properly or when the user can have only one device connected to a wireless network.
Choose Generate Backup code.
After clicking Generate Backup code, a text file is downloaded to your computer. This text file contains the backup keys that can be used. These are a one-time use only key. Do not lose them. If you press the button more than once, it generates additional text files, however, only the last set of numbers are valid for use.