ASP.NET Core Identity in a Web API

Are there any guides on how to set up ASP.NET Core Identity for a Web API?

Everything I find uses view models and has the register/login pages displayed on the server as a RazorPage.

MS's Intro document also does this - https://docs.microsoft.com/en-us/aspnet/core/security/authentication/identity?view=aspnetcore-6.0&tabs=visual-studio

This seems a very old style of set up.

I want my React client to display the register/login forms.

The Web API should just have a registration and login endpoint that returns a DTO. ASP.NET Core Identity being used to store the users in a database in the API, and manage authentication and authorization.

Am I barking up the wrong tree perhaps? Maybe ASP.NET Core Identity just doesn't work this way and I should instead use a hosted user management/authentication solution like AWS Cognito or Auth0?

Thanks