Shopify conversion tracking

shopify.js

<script type="text/javascript">
    var items = {{ order.line_items | json }};
    var item;
    var productsArray = [];

    for(var i = 0; i < items.length; i++) {
        item = { 
            'sku': items[ i ].variant.sku,
            'price': items[ i ].price,
            'size': items[ i ].variant.option2,
            'quantity': items[ i ].quantity
        }
        productsArray.push( item );
    }
    var shpfy_track = {                
        products: productsArray,
        transaction : '{{ order.order_number }}',
        amount: {{ order.total_price | money_without_currency }},
        currency: '{{ shop.currency }}'
    };    
</script>