If Two Factor Authentication (2FA) is enabled on your account this is where you will be prompted to enter an SMS code:

1. When logging into your account.
2. When changing any personal details in Admin> General details, i.e. the email address, telephone number and postal address.
3. When downloading your database in Admin> Maintenance> Download Database.
4. When accessing your back up codes.
5. When disabling 2FA.