Autofill One-Time Passcodes from Authenticator Chrome Extension

Instead of typing or copying and pasting one-time passcodes (OTP) from the Authenticator Google Chrome Extension, you can set it up to automatically fill the code into the designated spot.
 

1. Click on the Authenticator extension
2. Click on the wheel in the upper left corner 
3. Select "Preferences"
4. Toggle the button next to "Use Autofill" so that it is blue  
5. Click the x in the upper left corner

You're all set!