Marketing Cloud: Add to Cart Tracking Code for Shopify

<script type="text/javascript">
  var _etmc = _etmc || [];
  document.querySelector('.product-form__cart-submit').addEventListener('click',function () {
  _etmc.push(["setOrgId", "MID"]);  
  _etmc.push(["trackCart", { "cart": [
{"item" : "{{ product.handle }}", "quantity":  "{{ 1 }}", "price" : "{{ product.price | money_without_currency }}", "unique_id" : "{{ product.selected_or_first_available_variant.sku }}" },
{%- for item in cart.items -%}
      {"item" : "{{ item.product.handle }}", "quantity":  "{{ item.quantity }}", "price" : "{{ item.product.price | money_without_currency }}", "unique_id" : "{{ item.sku }}" },
{% endfor %}
]}]); 
  });
</script>