Once you’ve enabled 2-Factor Authentication, there are several additional settings that you can enable.
To enable SMS Verification, first navigate to Application Settings.
Then choose the Security & Privacy tab.
Scroll to the Add Additional Verification Steps heading. Then look for the Setup Text Message subheading. Select Set Up, then enter your phone number. Click next, and you’ll receive a verification code. Enter it in the box to complete the SMS Verification setup.