From this article, you'll find:
Security
You have the option to enable two-factor authentication. This means that when you log in to the booksalon system, you will need to enter a security code in addition to your username and password. Before activation, you need to download an app such as Authenticator or Google Authenticator from your app store.
Instructions for activation:
Log in to the system using your login details.
Select "Personal settings" in the top right corner.
Choose "Set up Two Factor Authentication".
Scan the displayed QR code using your authentication app (e.g. Google Authenticator) to generate the token.
Enter the token (code) found in the app into the appropriate field within the booksalon system.
Log out and log in again for the setting to take effect.
Done!
Instructions for removal:
Log in to the system using your login details.
Select "Personal settings" in the top right hand corner.
Choose "Remove Two Factor Authentication".
Enter the token (code) from the application to confirm removal.
Log out and log in again for the setting to take effect.