Here's the summary of the required tasks to set up our explicit flow:

• Install the Microsoft.AspNetCore.Authentication.Facebook package using NuGet
• Set up and configure the Facebook Authentication service in the Startup class
• Include the Facebook Client ID and Client Secret keys in our appsettings.json file
• Add the required action methods to our existing TokenController class
• Create a login.externalproviders.component.ts Angular component--and its .html template file--to perform the required client-side tasks that will trigger the whole thing

Let's do this.