Apps such as Google Authenticator on your phone (either Apple or Android) can be used with Float in order to access your account once 2-factor authentication has been enabled.
You can also use Desktop Authentication Apps in order to access your authentication code to enable you to log into Float once the secondary layer of security has been added.
Once downloaded, it is recommended that you keep the app available on your chosen device and do not delete it unless you intend to either switch your authentication method, or swap the device used.
Your Authenticator app provides you with a 6-digit code to log into Float. Without this code, you could be locked out of your account if you don't also have access to your backup codes.