What is authorization-code/callback in Github .Net sample


I just started developing application for OKTA. I am using the sample code from:

The project is working fine. But I am curious, the following route is not implemented by the project:


I use fiddler to capture the traffic and notice it did get call. I am wondering how the url can work without even being implemented?


This is a route created by the Okta.AspNet middleware. https://developer.okta.com/docs/guides/sign-into-web-app/aspnet/define-callback/