ASP.NET Core Web API and Angular CRUD

I am brand new to Angular and have gone through a lot of tutorials on how to create an ASP.NET Core Web API and Angular CRUD. The majority of the tutorials have both the web API and angular in a single solution. In a single solution, the controllers have the endpoints and know exactly where to go to consume the API.

I would like to learn to separate the front-end (Angular) and the back-end (Web API) into 2 distinct projects. However, I don't see the connectivity between the Angular project and the Web API. In other words, how does the Angular project know where to go to consume the API? Is all the magic in the "Startup.cs"?