Program.cs

using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Conventions;
using Worktastic.Data;

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.UseNpgsql(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = false)
    .AddRoles<IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>();
builder.Services.AddControllersWithViews();

var app = builder.Build();

using (var serviceScope = app.Services.CreateScope())
{
    var context = serviceScope.ServiceProvider.GetRequiredService<ApplicationDbContext>();
    context.Database.Migrate();
}

using (var scope = app.Services.CreateScope())
{
    var roleManager = scope.ServiceProvider.GetRequiredService<RoleManager<IdentityRole>>();
    var userManager = scope.ServiceProvider.GetRequiredService<UserManager<IdentityUser>>();
    string role = "Admin";

    if (!await roleManager.RoleExistsAsync(role))
    {
        await roleManager.CreateAsync(new IdentityRole(role));
    }

    if (await userManager.FindByNameAsync("admin@worktastic.com") == null)
    {
        var newUser = new IdentityUser()
        {
            UserName = "admin@worktastic.com",
            Email = "admin@worktastic.com",
        };
        var result = await userManager.CreateAsync(newUser, "Test.1234");
    }

    var user = await userManager.FindByNameAsync("admin@worktastic.com");
    await userManager.AddToRoleAsync(user!, role);
}

// 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();