title: Azure AD B2C + App Service + Functions : How to flow the auth?
body: <p>I have a Web App (VueJS + ASP .NET Core backend) hosted on Azure App Service and I use Azure AD B2C for authentication.  I also have a Functions App that I want to call from the client code but I’m not sure what’s the best way to flow the auth to the Functions.</p>
  
  <ul>
  <li>I can register the Functions App in B2C and set Easy Auth but how do I flow the already authenticated user from the client to the Function?</li>
  <li>I can create a custom JWT token and be done with it but is it possible to flow a B2C token to the Function?  If so, how do I validate the token?</li>
  </ul>