enrol.html

<h3><?php print_string("paymentrequired") ?></h3>
<p><b><?php echo get_string('cost', 'enrol_hitpay').": {$instance->currency} {$localisedcost}"; ?></b></p>

<p><?php print_string("paymentinstant") ?></p>
<div class="container">
    <div class="row">
        <div class="col-md-8 order-md-1">
            <form action="hitpay/checkout.php" method="POST" class="needs-validation">
                <input type="hidden" name="name" class="form-control" id="customer_name" placeholder=""
                       value="<?php echo $USER->firstname . ' ' . $USER->lastname; ?>">
                <input type="hidden" name="mobile" class="form-control" id="mobile" placeholder="Mobile"
                       value="<?php echo $USER->phone1; ?>">

                <input type="hidden" name="email" class="form-control" id="email"
                       value="<?php echo $USER->email; ?>">

                <input type="hidden" class="form-control" id="address" name="address"
                       value="<?php echo $USER->address; ?>">

                <input type="hidden" value="<?=p($cost) ?>" name="amount" id="total_amount" required/>
                <input type="hidden" value="<?php echo $course->fullname; ?>" name="coursename" id="coursename" required/>
                <input type="hidden" value="<?php echo $USER->id; ?>" name="userid" id="userid" required/>

                <input type="hidden" name="course_id" value="<?php echo $course->id; ?>" />

                <input type="hidden" name="instance_id" value="<?php echo $instance->id; ?>" />
                <input type="hidden" name="currency_code" value="<?php p($instance->currency) ?>" />

                <button class="paynowbutton" type="submit"><?php echo get_string('button_name', 'enrol_hitpay')?></button>
            </form>
        </div>
    </div>
</div>

<style>
    <?php
        include 'style_enrol_hitpay.css';
    ?>
</style>

<script>
    (function (window, document) {
        var loader = function () {
            var script = document.createElement("script"), tag = document.getElementsByTagName("script")[0];
            script.src = "https://sandbox.hitpay.com/embed.min.js?" + Math.random().toString(36).substring(7);
            tag.parentNode.insertBefore(script, tag);
        };

        window.addEventListener ? window.addEventListener("load", loader, false) : window.attachEvent("onload", loader);
    })(window, document);
</script>
<?php
    echo html_writer::end_div();
?>