Program.cs

using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using Microsoft.IdentityModel.Tokens;
using OrderManagementApi.Data;
using OrderManagementApi.Models;
using OrderManagementApi.Services;
using System.Text;

var builder = WebApplication.CreateBuilder(args);

builder.Configuration
    .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);

builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

//Service Layer Registry
builder.Services.AddScoped<IOrderService, OrderService>();

builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));

// Identity
builder.Services.AddIdentity<ApplicationUser, IdentityRole>(options =>
{
    options.Password.RequireDigit = true;
    options.Password.RequiredLength = 6;
    options.Password.RequireNonAlphanumeric = false;
    options.Password.RequireUppercase = false;
})
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddDefaultTokenProviders();

// JWT 
var jwtSettings = builder.Configuration.GetSection("JwtSettings");
var secretKey = jwtSettings["Secret"];

if (string.IsNullOrWhiteSpace(secretKey))
    throw new Exception("JWT Secret key missing in appsettings.json");

var key = Encoding.UTF8.GetBytes(secretKey);

builder.Services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
    options.RequireHttpsMetadata = false;
    options.SaveToken = true;

    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuer = true,
        ValidIssuer = jwtSettings["Issuer"],

        ValidateAudience = true,
        ValidAudience = jwtSettings["Audience"],

        ValidateIssuerSigningKey = true,
        IssuerSigningKey = new SymmetricSecurityKey(key),

        ValidateLifetime = true,
        ClockSkew = TimeSpan.Zero
    };
});

builder.Services.AddAuthorization();

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseAuthentication();
app.UseAuthorization();

app.MapControllers();

app.Run();