Unable to find endpoints. Invalid URI

I have this code on my controller

[Route("api/[controller]")]
[ApiController]
[Authorize(Roles = "Admin")]
public class AdminController : ControllerBase

[Route("api/[controller]")]
[ApiController]
[Authorize(Roles = "Admin")]
public class AdminController : ControllerBase

In other projects

https://localhost:<PORT>/api/Admin/...

https://localhost:<PORT>/api/Admin/...

would return the data. But now the URI is invalid.

As it is a .NET 8 project, I am unsure as to how to add swagger as well