If you'd like to show the product's sales on the product's page, e.g. on the product page "black shoes" we will only show recent sales of that shoe, here's what you should do:
In Shopify Store Admin go to
Online Store -> Themes -> Actions -> Edit Code -> Product.liquid
And add this code in the beginning of the file:
<script type="text/javascript">
window.dq=[{ n:"Notification Name", g: {{ product.id }} }];
</script>
Don't forget to change "Notificaiton Name" to the name of the Shopify Stream Notification.