Correct Purchase Event Tracking

checkout.html

// Script that tracks Purchase events at Shopify checkout to forward in GTM
// From GTM it can be sent to Google Ads, where Google Ads will process currency conversion
// However, ~20% of events will be blocked by ad-blockers, if you want to capture all events you will need a tool like Converge
// Contact me at jan [at] runconverge [dot] com to learn more.

<script>
window.dataLayer = window.dataLayer || [];
dataLayer.push({ ecommerce: null });
dataLayer.push({
  event: "purchase",
  ecommerce: {
      transaction_id: "{{ checkout.order_number}}",
      value: {{ checkout.subtotal_price | money_without_currency | replace:',','.' }},
      tax: {{ tax_price | times: 0.01 }},
      shipping: {{ shipping_price | times: 0.01 }},
      currency: "{{ order.currency }}", // Make sure you send the currency variable so Google Ads can convert themselves
      items: [
       {% for line_item in line_items %}{
        item_id: "{{ line_item.product_id }}",
        item_name: "{{ line_item.title | remove: "'" | remove: '"' }}",
        currency: "{{ order.currency }}",
        price: {{ line_item.final_price | times: 0.01 }},
        quantity: {{ line_item.quantity }}
      },{% endfor %}
 ]
  }
});
</script>