With two-factor authentication, you add an extra layer of security to your account in case your password is stolen. After you set up Two-Factor Verification, you’ll sign in to your account in two steps using:  Your password and the authentication code on your phone.

To enable Two Factor Authentication you go to Profile Settings. 

Click Enable two-factor authentication

Download one of the available authentication apps and click 'Next step'.  

Scan the QR code with your authenticator app

Next fill in the authentication code and click 'next step' to finalise your two-factor authentication.