GA4 Begin Checkout

<script>
dataLayer.push({ ecommerce: null });  // Clear the previous ecommerce object.
dataLayer.push({
  event: "begin_checkout",
  ecommerce: {
    items: [
    {
      item_id: "SKU_12345",
      item_name: "Stan and Friends Tee",
      affiliation: "Google Merchandise Store",
      coupon: "SUMMER_FUN",
      currency: "USD",
      discount: 2.22,
      index: 0,
      item_brand: "Google",
      item_category: "Apparel",
      item_category2: "Adult",
      item_category3: "Shirts",
      item_category4: "Crew",
      item_category5: "Short sleeve",
      item_list_id: "related_products",
      item_list_name: "Related Products",
      item_variant: "green",
      location_id: "L_12345",
      price: 9.99,
      quantity: 1
    }
    ]
  }
});
</script>