To open the payment module I got the following code and inserted it on the page as html:
<a class="btn-payrexx-modal" href="https://[secret].payrexx.com/pay?tid=[secret]">
Bezahlen
</a>
<script type="text/javascript" src="https://media.payrexx.com/modal/v1/modal.min.js?v=1.7"></script>
<script type="text/javascript">
jQuery(".btn-payrexx-modal").payrexxModal();
</script>
If you click on it, you will be redirected instead of the lightbox opening. What is the problem?