Token Based Authentication (edit)
https://scotch.io/tutorials/the-ins-and-outs-of-token-based-authentication
JSON Web Tokens
https://scotch.io/tutorials/the-anatomy-of-a-json-web-token
Source Samples
https://github.com/MikeWasson/LocalAccountsApp
Bearer Token Authentication in ASP.NET Core
https://devblogs.microsoft.com/aspnet/bearer-token-authentication-in-asp-net-core/
WebApi OAuth
https://blogs.msdn.microsoft.com/mvpawardprogram/2017/05/02/adding-webapi-oauth-auth/