Program.cs

using Identity.Data;
using Identity.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;

namespace Identity
{
    public class Program
    {
        public static async Task Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            // Add services to the container.
            var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? throw new InvalidOperationException("Connection string 'DefaultConnection' not found.");
            builder.Services.AddDbContext<ApplicationDbContext>(options =>
                options.UseSqlServer(connectionString));



            builder.Services.AddDatabaseDeveloperPageExceptionFilter();

            builder.Services.AddIdentity<ApplicationUser, IdentityRole>()
            .AddEntityFrameworkStores<ApplicationDbContext>()
            .AddDefaultUI()
            .AddDefaultTokenProviders();
            builder.Services.AddControllersWithViews();
            builder.Services.AddRazorPages();

            var app = builder.Build();

            await Configure(app);
          

            // Configure the HTTP request pipeline.
            if (app.Environment.IsDevelopment())
            {
                app.UseMigrationsEndPoint();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");
            app.MapRazorPages();
         
            app.Run();

            static async Task Configure(WebApplication host)
            {
                using var scope = host.Services.CreateScope();
                var services = scope.ServiceProvider;

                try
                {
                    var dbContext = services.GetRequiredService<ApplicationDbContext>();

                    var userManager = services.GetRequiredService<UserManager<ApplicationUser>>();
                    var roleManager = services.GetRequiredService<RoleManager<IdentityRole>>();
                    await ContextSeed.SeedRolesAsync(userManager, roleManager);
                }
                catch (Exception ex)
                {
                    throw;
                }
            }

        }
    }
}