Google Invisible reCAPTCHA

<div class="g-recaptcha" data-sitekey="{/form/site_key}" data-size="invisible"></div>

<form>
                    <button type="submit" class="btn btn-primary btn-footer g-recaptcha" data-sitekey="RECAPTCHA_SITEKEY" data-callback="onSubmitRecaptcha" data-size="invisible">Отправить</button>
</form>

function onSubmitRecaptcha(token) {
    var footer = $("#form");
    if(footer.valid())
    {
        $.ajax({
            url: footer.attr("action"),
            type: footer.attr("method") ? footer.attr("method") : "get",
            data: footer.serialize(),
            beforeSend: function() {
                $.loadingScreen('show');
            },
            success: function (data) {
                if(parseInt(data.code) > 0)
                {
                    footer.hide();
                    footer.parent().find('.success_message').html(data.message);
                }
                else
                {
                    footer.find('.error_message').html(data.message);
                }
            },
            error: function (data) {
                console.log('Error', data);
            },
            complete: function() {
                $.loadingScreen('hide');
            },
            dataType: "json"
        })
    }
    else
    {
        grecaptcha.reset() ;
    }
}

<div class="g-recaptcha" data-sitekey="{/form/site_key}" data-callback="onloadCallback" data-size="invisible"></div>

<script>
         function onloadCallback() {
         grecaptcha.execute();
      }
      </script>

?onload=onloadCallback

<script src="https://www.google.com/recaptcha/api.js?onload=onloadCallback" async defer></script>

if ($oShop->use_captcha == 0 || $siteuser_id > 0 || Core_Captcha::valid(Core_Array::getPost('captcha_id'), Core_Array::getPost('captcha')))
{

Core_Captcha::valid(Core_Array::getPost('captcha_id'), Core_Array::getPost('captcha'))

function answer(){
   $sSecretKey = "xxx"; // Указывается секретный ключ reCAPTCHA
      if (Core_Array::getPost('g-recaptcha-response'))
    {
      $sResponse = Core_Array::getPost('g-recaptcha-response');

         $sUrl = 'https://www.google.com/recaptcha/api/siteverify?secret=' . $sSecretKey . "&response=" . $sResponse;    

         $aAnswer = json_decode(file_get_contents($sUrl), TRUE);

               if ($aAnswer['success'])
            {
               return TRUE;
            }
              else
              {
            Core_Log::instance()
                ->clear()
                ->status(Core_Log::$ERROR)->write('Google Recaptcha: ' . $aAnswer['error-codes'][0]);
              }
            }
        }

if (]if ($oShop->use_captcha == 0 || $siteuser_id > 0 || answer())
{

$sResponse = Core_Array::getPost('g-recaptcha-response');
$sUrl = 'https://www.google.com/recaptcha/api/siteverify?secret=' . $sSecretKey . "&response=" . $sResponse;
$aAnswer = json_decode(file_get_contents($sUrl), TRUE);