General question about ASP.NET Angular Single Page App Project Template using Authentication

Question

I started a new project using ASP.NET Single Page App with Authentication set to individual accounts. When I launch this project template, everything seems to work fine, but I'm confused because I don't understand how some parts of the app are injected from the source code. For instance, when I click on the "Login" menu I can see a title where "Use another service to log in." is displayed . When I search in the entire solution, I cannot find this part in the code ( searching in files in VSCode, even including node_modules folder ). I navigated also through the entire Angular Client App, but this part wasn't present in the source code. This is the same for the login form : I searched for the template where the login form is contained without finding it. Where are these elements injected from ? Is this part working under the hood or am i missing something ?
Thanks a lot for your help !

Answer 1

One of the advantages of razor pages is that the razor page and code can be built into a library. The source of the form is in the authentication library.

Answer 2

I guess this is injected from SigninManager in Shared/LoginPartial.cshtml