ASP.Net Core Identity UI 2.1 EmailSender registration on Startup.cs

Startup.cs

// ... Usings
using Microsoft.AspNetCore.Identity.UI.Services;
using MailSenderApp.Services;

namespace MailSenderApp {
    public class Startup {
        
        // ... Startup initializer and other methods
        
        public void ConfigureServices(IServiceCollection services)
        {
            // ... Other services
            services.AddDefaultIdentity<IdentityUser>().AddEntityFrameworkStores<ApplicationDbContext>();

            services.AddTransient<IEmailSender, EmailSender>();

            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
        }
    }
}