Two Factor Authentication – Optional
When Two Factor Authentication is setup as “Optional”, you will have to manually enable/disable two factor authentication for your users. Select the user and click “Enable 2FA” or “Disable 2FA” to enable or disable two factor authentication for the users.
For users with Two Factor Authentication enabled, they will have to verify themselves using two step verification process.
Note : For “Optional” setup, whenever you add new users, and you want them to use Two Factor Authentication, then you will have manually enable it for them as mentioned above.