Two-Step Verification is a feature that adds an extra layer of security by asking you to enter a unique security code in addition to your password on computers and devices that you have not designated as trusted.
To enable Two-Step Verification on your account:
1. Go to your account's Security Settings.
2. Change the Two-Step Verification setting to "Yes" and click the "Save Changes" button.
3. Scan the displayed QR code with a valid authenticator mobile app, such as Authy or Google Authenticator.
4. Enter the passcode that was generated through the authenticator app and click the "Validate" button.
5. Return to your Security Settings and click the "Get backup code" link.
6. Save your backup code in a safe place.