'Error: reCAPTCHA placeholder element must be an element or id' with Sendinblue/Wordpress form

[admin]

I'm trying to add a reCaptcha (v3 invisible) with the Sendinblue plugin in wordpress for my newsletters' but I have an error in console : Unhandled Promise Rejection: Error: reCAPTCHA placeholder element must be an element or id
The website: <a href="https://www.pharmabox.app" rel="nofollow noreferrer">https://www.pharmabox.app</a>
Does anyone have an idea to resolve my problem ?
Thank you very much
(Sorry for my bad English, I'm French )

<script type="text/javascript">
var gCaptchaSibWidget;
var onloadSibCallback = function() {
   var element = document.getElementsByClassName('sib-default-btn');
   gCaptchaSibWidget = grecaptcha.render(element[0], {
      'sitekey': '6Lcl_NQbAAAAACzZc33DPbjoQrf8IcvgQu5xvLo6',
      'callback': sibVerifyCallback
   });
};
</script>

<script src="https://www.google.com/recaptcha/api.js?onload=onloadSibCallback&render=explicit" async defer></script>
<form id="sib_signup_form_1" method="post" class="sib_signup_form">```