ga4-purchase.liquid

<script>
    window.dataLayer = window.dataLayer || [];
    dataLayer.push({ ecommerce: null });
    setTimeout(function (){

        dataLayer.push({
            event: "purchase",
            ecommerce: {
                transaction_id: {{ order.id }},
                shipping: {{ order.shipping_price | money_without_currency }},
                value: {{ total_price }},
                tax: {{ order.tax_price | money_without_currency }},
                currency: "{{ order.currency }}",
                items: [
                        {% for line_item in line_items %}{
                        item_id: "{{ line_item.sku }}",
                        item_name: "{{ line_item.title | remove: "'" | remove: '"' }}",
                        index: {{ forloop.index }},
                        item_brand: '{{ line_item.product.vendor }}',
                        {% for collection in line_item.product.collections %}
                        {% if forloop.index == 1 %}
                        item_category: '{{ collection.title }}',
                        {% else %}
                        item_category{{ forloop.index }}: '{{ collection.title }}',
                        {% endif %}
                        {% endfor %}
                        item_variant: '{{ line_item.variant.title }}',
                        currency: '{{ shop.currency }}',
                        price: {{ line_item.final_price | times: 0.01 }},
                        quantity: {{ line_item.quantity }}
                    },
                    {% endfor %}
                ]
                {% if customer %},user_id:{{ order.customer.id }}{% endif %}
            }
        });
    },1000);

</script>