How do I get the authenticator app verification code?

To get the verification code, open your authenticator app on your phone or tablet. This is the app you used to set up Authenticator App Verification. In the app you should see a section that shows your FreeTaxUSA account username as well as a 6-digit number. Enter that 6-digit number on this screen.

Verification codes generally expire after a short amount of time so be sure you're using the most recent 6-digit code. Your authenticator app should show you a new code right when the old one expires.