Using ‘UseMvc’ to configure MVC is not supported while using Endpoint Routing

I found the solution, in the following official documentation “Migrate from ASP.NET Core 2.2 to 3.0”:

There are 3 approaches:

1. Replace UseMvc or UseSignalR with UseEndpoints.

In my case, the result looked like that

  public class Startup
{

    public void ConfigureServices(IServiceCollection services)
    {
        //Old Way
        services.AddMvc();
        // New Ways
        //services.AddRazorPages();
    }


    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseStaticFiles();
        app.UseRouting();
        app.UseCors();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}");
        });

    }
}

OR
2. Use AddControllers() and UseEndpoints()

public class Startup
{

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllers();
    }


    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseStaticFiles();
        app.UseRouting();
        app.UseCors();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });

    }
}

OR
3. Disable endpoint Routing. As the exception message suggests and as mentioned in the following section of documentation: use mvcwithout endpoint routing

services.AddMvc(options => options.EnableEndpointRouting = false);
//OR
services.AddControllers(options => options.EnableEndpointRouting = false);