Implement ShopVote EasyReviews Addon

im currently trying to implement EasyReviews Addon of shopvote to collect customer ratings. I added the HTML snippet

 <!-- BEGIN - EasyReviews Addon | www.shopvote.de -->
 <div id="srt-customer-data" style="display:none;">
    <span id="srt-customer-email"><?= $email ?></span>
<span id="srt-customer-reference"><?= $order_number ?></span>

in success.phtml which runs after order completes and the

<!-- BEGIN - Javascript EasyReviews Addon -->
<script src="https://feedback.shopvote.de/srt-v4.min.js"></script>
<script type="text/javascript">
  var myToken = "03e39758269afsdfsgdsgsdfsdteste06ef3ca7bfsdfs243";
  var mySrc = ('https:' === document.location.protocol ? 'https' : 'http');
  var myLanguage = 'DE';
  loadSRT(myToken, mySrc);
</script>
<!-- END - Javascript EasyReviews Addon -->

After the order completion a popup should appear but it does not although i checked in network tab and the script runs. I don’t know what is the problem and how to fix it. Please help me if you have experience with it.
Thank you in advance.