The backup codes option is available after configuring OTP(Email,Mobile App or Short code).This option is present on the Two Factor Authentication step for the Netextender,MobileConnect or Virtual host login screen
This is by design.
The backup codes are considered safe and the option is provided to help the users who cannot access the their E-mail box, Cell-phone or Mobile App.
The user only can generate the backup codes after successfully login to the portal page.(Using the username/password and OTP)
There are 8 backup codes generated at one time
The backup code will be expired after using it to login. A code cannot be reused.
The backup code only can be used in Two Factor Authentication step.This option is available only after the user is authenticated.