Need Help with Custom Pixel Code for Pushing Line Items to Google Tag Manager

[ashishjangir]

I'm working on adding a custom pixel script to my Shopify store that pushes purchase event data, including detailed line items, to Google Tag Manager. I've written the following Liquid code to achieve this:

{% assign items = '' %}

  {% for line_item in order.line_items %}
    {% assign variant = '' %} 
    {% if line_item.title contains 'Mini' %}
      {% assign variant = 'Mini' %}
    {% elsif line_item.title contains 'Small' %}
      {% assign variant = 'Small' %}
    {% elsif line_item.title contains 'Standard' %}
      {% assign variant = 'Standard' %}
    {% endif %}

    {% capture current_item %}
    {
      "item_id": "{{ line_item.variant.sku }}",
      "item_name": "{{ line_item.title }}",
      "variant": "{{ variant }}",
      "coupon": "{{ order.discount_codes.first.code }}",
      "discount": {{ line_item.total_discount | money_without_currency }},
      "item_brand": "Kori Krill Oil",
      "item_category": "{{ line_item.product.type }}",
      "price": {{ line_item.price | money_without_currency }},
      "quantity": {{ line_item.quantity }}
    }
    {% endcapture %}

    {% if forloop.first %}
      {% assign items = current_item %}
    {% else %}
      {% assign items = items | append: ',' | append: current_item %}
    {% endif %}
  {% endfor %}

  var items = [{% raw %}{{ items }}{% endraw %}];

  window.dataLayer = window.dataLayer || [];
  window.dataLayer.push({
    event: 'purchase',
    event_category: 'purchase',
    event_action: 'purchase',
    currency: "{{ order.currency }}",
    transaction_id: "{{ order.order_number }}",
    value: {{ order.total_price | money_without_currency }},
    tax: {{ order.tax_total | money_without_currency }},
    shipping: {{ order.shipping_price | money_without_currency }},
    coupon: "{{ order.discount_codes.first.code }}",
    items: items
  });

Same error we are facing with installing other pixels. 

[Bhawlad]

What is this