enrol.html

<div align="center">

<p><?php print_string("paymentrequired") ?></p>
<p><b><?php echo $instancename; ?></b></p>
<p><b><?php echo get_string("cost").": {$instance->currency} {$localisedcost}"; ?></b></p>
<p><?php print_string("paymentinstant") ?></p>

<form action="" method="POST">
  <script
    src="https://checkout.stripe.com/checkout.js" class="stripe-button"
    data-key='<?php echo "{$instance->stripeapikey}" ?>'
    data-amount='<?php echo "{$instance->currency}"?>'
    data-name="Demo Site"
    data-description='<?php echo "{$instance->currency} {$localisedcost}"?>'
  >
  </script>
</form>

</div>