To activate two-factor authentication, go to your Account page and turn on the Two-factor authentication toggle under Security.
P.S. If you're using FTP or WebDAV while 2FA is enabled, you will need to log in using a combination of your password followed immediately by the one-time password from your authenticator app - with no blank space between them. It should look like this: passwordonetimepassword.
Recovery
Once 2FA is enabled, we'll provide you with recovery codes. They are important if you ever lose access to your authenticator app. Don't lose these codes—you may need them to regain access to your account.