Digict on "Woocommerce variables - Reseller Ratings"

I'm trying to integrate the Reseller Ratings code into my Woocommerce "Thank you" page.

The code requires that the email and order number be passed to the script, but nothing I enter works.

Here's an example of the code:

<script type="text/javascript">
var _rrES = {
    seller_id: XXXXXXX,
    email: "customer@home.com",
    invoice: "INVOICE NUMBER"};
(function() {
    var s=document.createElement('script');s.type='text/javascript';s.async=true;
    s.src="https://www.resellerratings.com/popup/include/popup.js";var ss=document.getElementsByTagName('script')[0];
    ss.parentNode.insertBefore(s,ss);
})();
</script>

I've tried various things but this is my latest attempt which does not work either.

<script type="text/javascript">
var _rrES = {
    seller_id: XXXXXXXX,
    email: "<?php echo $current_user->user_email; ?>",
    invoice: "<?php echo $order->get_order_number(); ?>"};
(function() {
    var s=document.createElement('script');s.type='text/javascript';s.async=true;
    s.src="https://www.resellerratings.com/popup/include/popup.js";var ss=document.getElementsByTagName('script')[0];
    ss.parentNode.insertBefore(s,ss);
})();
</script>

Can anyone help me get the right variables into that code please!