Invisible reCAPTCHA

gistfile1.txt

<script src="https://www.google.com/recaptcha/api.js" async defer></script>
<script>
  var element = document.getElementById("payment_card_confirm");
  element.classList.add("g-recaptcha");
  element.dataset.sitekey = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
  element.dataset.callback = "onSubmitCaptcha";
  
  function onSubmitCaptcha(token) {
    document.getElementById("payment_form").submit();
  }
</script>