Bigcommerce
Tag Manager
https://support.bigcommerce.com/articles/Public/Accessing-and-Customizing-Template-Files
https://support.bigcommerce.com/articles/Public/Passing-Order-Data-to-Affiliate-Programs#tracking-variables adding Conversion Tracking
Advanced settings -> Affiliate Conversion Tracking
Conversion Tracking Code
<script>
var dataLayer = window.dataLayer || [];
dataLayer.push({'order_id' : '%%ORDER_ID%%','order_value' : '%%ORDER_AMOUNT%%', 'event' : 'order-submitted'});
</script>