Unable to get auth token with Twitter 2.0 API

I set all the new tokens fields, pick Get New Access Token, it shows the Get New Access Token dialog, then twitter comes up and says “You weren’t able to give access to the App. Go back and try logging in again.” and a back button. But going back just shows my twitter profile and no callback ever happens. I set the callback URL in twitter to be postman’s. Am I missing something?