Seeking help for conversion tracking from wix shop

[affrabby]

Hi there,

Can fire my postback pixel from my wix shop but unable to receive cart value/order total value. As wix dont have dynamic parameter to receive the value. They only have api, Can anyone help me to send the order total value from wix shop to my postback pixel.
<script>
var order_total = 'order.totals.total';
var order_id = 'order.number';
var params = '&payout=' + order_total + '&txid=' + order_id
var sid = window.localStorage.getItem('sid');
var req = new XMLHttpRequest();
req.open('GET',
'https://trk.example.com/postback?cid=' + sid + params);
req.send();

</script>

Wix API: https://www.wix.com/velo/reference/$w/thankyoupage/getorder

I was trying this code but conversion firing but still payout and order number not tracking. I don't have enough coding knowledge maybe someting that i missing out. @Nick maybe you can have a look