Got this working with .Net Core 3.1 as follows
1.Make sure you place the UseCors code between app.UseRouting(); and app.UseAuthentication();
app.UseHttpsRedirection();
app.UseRouting();
app.UseCors("CorsApi");
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints => {
endpoints.MapControllers();
});
2.Then place this code in the ConfigureServices method
services.AddCors(options =>
{
options.AddPolicy("CorsApi",
builder => builder.WithOrigins("http://localhost:4200", "http://mywebsite.com")
.AllowAnyHeader()
.AllowAnyMethod());
});
3.And above the base controller I placed this
[EnableCors("CorsApi")]
[Route("api/[controller]")]
[ApiController]
public class BaseController : ControllerBase
Now all my controllers will inherit from the BaseController and will have CORS enabled