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>

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