Program.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.AspNetCore.Identity;
using Demo_API.Data;
using Demo_API.Models;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Microsoft.AspNetCore.Cors;
using System.Text;

var builder = WebApplication.CreateBuilder(args);
ConfigurationManager configuration = builder.Configuration;


var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
var serverVersion = new MySqlServerVersion(new Version(8, 0, 28));
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseMySql(connectionString, serverVersion));

// builder.Services.AddDefaultIdentity<IdentityUser>()
//     .AddEntityFrameworkStores<ApplicationDbContext>();

builder.Services.AddIdentity<ApplicationUser,IdentityRole>()
            .AddRoles<IdentityRole>()
            .AddEntityFrameworkStores<ApplicationDbContext>()
            .AddDefaultTokenProviders();

builder.Services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
    options.SaveToken = true;
    options.RequireHttpsMetadata = false;
    options.TokenValidationParameters = new TokenValidationParameters()
    {
        ValidateIssuer = true,
        ValidateAudience = true,
        ValidateLifetime = true,
        ValidateIssuerSigningKey = true,
        ClockSkew = TimeSpan.Zero,

        ValidAudience = configuration["JWT:ValidAudience"],
        ValidIssuer = configuration["JWT:ValidIssuer"],
        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(configuration["JWT:Secret"] ?? throw new ArgumentNullException("An error occurred : It seems the JWT issuer signing key is null. Please fix the issue in /appsettings.json")))
    };
});

// Add services to the container.

builder.Services.AddCors(options => 
{
    options.AddPolicy(name:"AllowOrigin", 
    builder => 
    {
        builder.WithOrigins("http://localhost:3000")
            .AllowAnyHeader()
            .AllowAnyMethod();
    });
});

builder.Services.AddControllers();
builder.Services.AddApiVersioning(config =>
    {
         config.AssumeDefaultVersionWhenUnspecified = true;
    });
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();


using (var scope = app.Services.CreateScope()) {
    var services = scope.ServiceProvider;

    try {
        var context = services.GetRequiredService<ApplicationDbContext>();
        context.Database.Migrate();

        var config = app.Services.GetRequiredService<IConfiguration>();
        // var userList = config.GetSection("userList").Get<List<string>>();
        IConfigurationSection Admin = config.GetSection("Admin");

        DummyData.Initialize(services, Admin).Wait();
    }
    catch (Exception ex) {
        var logger = services.GetRequiredService<ILogger<Program>>();
        logger.LogError(ex, "An error occurred adding users.");
    }
}

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseCors("AllowOrigin");

app.UseHttpsRedirection();

app.UseAuthorization();

app.MapControllers();

app.Run();