If you are enable 2-Step Verification and you want to use more extra layer of security to your account. You sign in with something you know (your password) and something you have (a code sent to your phone).
Next step is :- Go to your login account and select to start and follow all steps to setup process. After finished you get 2-2-Step Verification settings page and review your settings, add multiple verification methods from which you login again you get text message of a verification code. You also have the option of using a Security Key for 2-Step Verification. Dial Gmail support number for help 1(505) 384-8224 or visit http://www.gmailcustomerservicenumber.us/