@gfritz I was just about to come here to write this exact thing. Did some digging and found where to put the code yesterday! 
Thanks so much!
I’m currently trying to figure out how to use the users-permissions fetchAuthenticatedUser method as my users never actually log in with the /auth/xxx endpoints as I’m building a React native app so I don’t have the luxury of callback URLs.
I am able to call my Auth0 domain int hat block to verify that the user is properly authenticated though so that’s likely a separate issue.
Thanks again, been stuck for days!