To enable Two-Step Verification:
- Go to Advanced Security Settings.
- Click Get Started to set-up Two-Step Verification.
- Add your primary phone number (this phone must be able to receive SMS messages) or download and configure an authenticator app and click Send code.
- Enter the code that was sent to your phone number or generated through the authenticator app and click Verify code and continue.
- Do either of the following:
- Add a back-up phone number and decide on delivery format (text message or voice call).
- Download and configure an authenticator app. This will allow you to generate security codes when you're unable to receive messages to your device.
Now, you're enable the Two-Step Verification for your account.
Note: You won't be able to turn on Two-Step Verification without adding a back-up phone number. This is so that you have a back-up option to receive a security code if you no longer have access to your primary mobile device.