Google Tag Shopify Purchase

<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-EXAMPLE"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-EXAMPLE');
{% if first_time_accessed %}
gtag("event", "purchase", {
    transaction_id: "{{ checkout.order_id }}",
    value: {{ total_price | times: 0.01 }},
    tax: {{ tax_price | times: 0.01 }},
    shipping: {{ shipping_price | times: 0.01 }},
    currency: "{{ checkout.currency }}",
    items: [
     {% for line_item in line_items %}
     {
      item_id: "{{ line_item.product_id }}",
      item_name: "{{ line_item.title | remove: "'" | remove: '"' }}",
      currency: "{{ checkout.currency }}",
      price: {{ line_item.original_price | times: 0.01 }},
      quantity: {{ line_item.quantity }}
    },
    {% endfor %}
    ]
});
{% endif %}
</script>

It’s based on Shopify’s own recommendation for conversion tracking on the order status page. See https://help.shopify.com/en/manual/orders/status-tracking/customize-order-status/add-conversion-tracking

So if their documentation isn’t right, you might want to customize it, but it works for my Shopify store.

Yeah I don't think that help page is right any more. Check your store orders for anything with a confirmation number in the order activity and then check to see if that order was tracked by GA4.

Mine all have an order number, but feel free to customize as you need.