Something wrong with cookie authentication in ASP.NET Core MVC

How to use cookie authentication but not ASP.NET Core Identity? It is my controller.It didn't work when I click submit. Can someone give me advice?

public IActionResult Login()
    {
        return View();
    }
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Login(db_user _User)
    {

        if (ModelState.IsValid)
        {   
            if (_User.UserName != "123" && _User.UserPassword != "123")
            {
                ViewData["ErrorMessage"] = "error!!";
                return View();
            }

            
            var claims = new List<Claim>   
            {
                new Claim(ClaimTypes.Name, _User.UserName),
                
            };

            
            var claimsIdentity = new ClaimsIdentity(
                                       claims, CookieAuthenticationDefaults.AuthenticationScheme);

            var authProperties = new AuthenticationProperties
            {
                //AllowRefresh = <bool>,
                // Refreshing the authentication session should be allowed.

                //ExpiresUtc = DateTimeOffset.UtcNow.AddMinutes(10), 
                // The time at which the authentication ticket expires. A 
                // value set here overrides the ExpireTimeSpan option of 
                // CookieAuthenticationOptions set with AddCookie.

                //IsPersistent = true,
                // Whether the authentication session is persisted across 
                // multiple requests. When used with cookies, controls
                // whether the cookie's lifetime is absolute (matching the
                // lifetime of the authentication ticket) or session-based.

                //IssuedUtc = <DateTimeOffset>,
                // The time at which the authentication ticket was issued.

                //RedirectUri = <string>
                // The full path or absolute URI to be used as an http redirect response value.
            };

            // ***  Login *********
            HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme,
                                                    new ClaimsPrincipal(claimsIdentity),
                                                    authProperties);
            #endregion

            return Content("<h3>Welcome</h3>");
        }

        // Something failed. Redisplay the form.
        return View();
    }
    public async Task<IActionResult> Logout()
    {
        
        await HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);

         return RedirectToAction("Index", "Home");
    }

It is my model

    namespace Cookie2.Model
{
    public class db_user
    {
        public string UserName { get; set; }
        public string UserPassword { get; set; }
    }
}

It is my .cshtml

 @model Cookie2.Model.db_user
    


@{
    ViewBag.Title = "title";
    Layout = "_Layout";
}


    <h2>Login</h2>
    <form asp-action="Index" asp-controller="Login" method="post">
        <label asp-for="UserName">
            <input asp-for="UserName">
        </label>
        <br />
        <label asp-for="UserPassword">
            <input asp-for="UserPassword">
        </label>
        <br>
        <button>Submit</button>
    </form>

It is startup.cs

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllersWithViews();

        services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
                .AddCookie(options =>
                {
                    options.AccessDeniedPath = "/Home/AccessDeny";
                    options.LoginPath = "/Home/Login";
                }
            
            
            );
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthentication();

        app.UseAuthorization();

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

appreciation appreciation appreciation appreciation appreciation appreciation appreciation appreciation appreciation appreciation appreciation appreciation appreciation appreciation