public void ConfigureServices(IServiceCollection services)
{
  services.Configure<CookiepolicyOptions>(options =>
  {
    // This lambda determines whether user consent for non-essential cookies is needed for a given request.
    options.CheckConsentNeeded = context => true;
    options.MinimumSameSITePolicy = SameSiteMode.None;
  });
  // GeetestOptions中配置id 与 key
  services.AddGeetest(opt=>{
        opt.Id = "e2697c763685a34be93a7d255ee06b59";
        opt.Key = "7882a2d954106041a731f5e10038982a";
      });
  services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}

Task<GeeTestRegisterResult> Register(string userId = null, string clientType = "unknown", string ipAddress = "unknown")

Task<bool> Validate(GeetestValidateinput input)

PRivate readonly GeetestManager _geetestManager;
public HomeController(GeetestManager geetestManager)
{
  _geetestManager = geetestManager;
}
public async Task<GeeTestRegisterResult> GeetestRegister()
{
  return await _geetestManager.Register(clientType: "web", ipAddress: "127.0.0.1");
}

public async Task<bool> GeetestValidate(GeetestValidateInput input)
{
  return await _geetestManager.Validate(input);
}

<script type="text/javascript" src="https://static.geetest.COM/static/tools/gt.js"></script>

<h2>Getest</h2>
<div id="geetestform">
  <input type="hidden" name="geetest_challenge" id="geetest_challenge">
  <input type="hidden" name="geetest_validate" id="geetest_validate">
  <input type="hidden" name="geetest_seccode" id="geetest_seccode">
</div>
<button class="form-control BTn-default" id="validate">点我验证</button>

$(function() {
  $.ajax({
    url: "/home/GeetestRegister",
    type: "get",
    dataType: "json",
    success: function(data) {
      // 使用Offline判断是否是离线验证
      offline = !data.success;
      initGeetest({
        // 以下配置参数来自服务端 SDK
        gt: data.gt,
        challenge: data.challenge,
        offline: !data.success,
        new_captcha: true,
        product: "float",
        width: "100%"
      },function(){
        // 初始化元素
        captchaObj.appendTo(document.getElementById('geetestform'));
      })
    }
  });
});

$("#validate").click(() => {
  VAR validate = captchaObj.getValidate();
  if (validate === undefined || !validate) {
    alert("请进行验证");
    return;
  }

  $.ajax({
    url: "/home/GeetestValidate",
    method:"post",
    data: {
      offline: offline,
      challenge: validate.geetest_challenge,
      validate: validate.geetest_validate,
      seccode: validate.geetest_seccode
    },
    success: function(res) {
      if (res) {
        alert("二次校验状态成功! 重置验证状态");
        captchaObj.reset();
      } else {
        alert("二次校验状态返回失败! 重置验证状态");
        captchaObj.reset();
      }
    }
  });
});