Select Enable under the Text Message Delivery (SMS) option to choose that method. Enter your mobile phone number and choose Send Code to receive a randomly generated code by text message (SMS). Enter the Access Code in Step 3 and click Register to complete the registration.  

Upon receiving notification of Success, click Continue.

Once registered, the code sent via SMS will be valid for 30 minutes. If an agency employee tries to log in 30 minutes after receiving the code, he/she will need to log in again and re-enable the Text Message Delivery (SMS) Two-Factor Authentication process to receive a new code.  

Once registered, and once daily, after entering your username and password you will be prompted to enter the code sent via SMS to complete the login process.