@addTagHelper *, DNTCaptcha.Core

using DNTCaptcha.Core;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();
// Add Dnt captcha
IWebHostEnvironment _env = builder.Environment;

builder.Services.AddDNTCaptcha(options =>
{
    options.UseCookieStorageProvider(SameSiteMode.Strict)
    .AbsoluteExpiration(minutes: 7)
    .ShowThousandsSeparators(false)
    .WithNoise(pixelsDensity: 25, linesCount: 3)
    .WithEncryptionKey("This is my secure key!")
    .InputNames(// This is optional. Change it if you don't like the default names.
        new DNTCaptchaComponent
        {
            CaptchaHiddenInputName = "DNT_CaptchaText",
            CaptchaHiddenTokenName = "DNT_CaptchaToken",
            CaptchaInputName = "DNT_CaptchaInputText"
        })
    .Identifier("dnt_Captcha")// This is optional. Change it if you don't like its default name.
    ;
});
var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    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.Run();

[HttpPost, ValidateAntiForgeryToken]
        [ValidateDNTCaptcha(
            ErrorMessage = "Please Enter Valid Captcha",
            CaptchaGeneratorLanguage = Language.English,
            CaptchaGeneratorDisplayMode = DisplayMode.ShowDigits)]
        public IActionResult Login(LoginModel model)
        {
            if (ModelState.IsValid)
            {
                return View();
            }
            ViewBag.message = "Login Successfull!";
            return View();
        }

using core.captcha.Models;
using DNTCaptcha.Core;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;

namespace core.captcha.Controllers
{
    public class DntCaptchaController : Controller
    {
        private readonly IDNTCaptchaValidatorService _validatorService;
        private readonly IOptions<DNTCaptchaOptions> _captchaOptions;

        public DntCaptchaController(IDNTCaptchaValidatorService validatorService,
            IOptions<DNTCaptchaOptions> captchaOptions)
        {
            _validatorService = validatorService;
            _captchaOptions = captchaOptions;
        }

        [HttpGet]
        public IActionResult Login()
        {
            return View();
        }

         [HttpPost, ValidateAntiForgeryToken]
        public IActionResult Login(LoginModel model)
        {
            if (!ModelState.IsValid)
            {
                return View(model);
            }
            if (!_validatorService.HasRequestValidCaptchaEntry(Language.English, DisplayMode.ShowDigits))
            {
                this.ModelState.AddModelError(_captchaOptions.Value.CaptchaComponent.CaptchaInputName, "Please Enter Valid Captcha.");
                return View();
            }
            ViewBag.message = "Login Successfull!";
            return View();
        }
    }
}