ASP.NET Core + ReactJS

Hello,
I built a Web API in asp.net core 2.0 and building the front-end in ReactJS.
How can I create token that is valid for both the SPA and the API?

EDIT:
I can already login to the front-end but of course the token is invalid for the back end.
I’m new to both ReactJS and Auth0 so any suggestions are much appreciated.

I found a similar post here: http://community.auth0.com/questions/6828/aspnet-core-vuejs

After following the instructions I solved my issue