Purchase DataLayer

        {
    "transaction_id": "T_12345_1",
    "value": 30.03,
    "tax": 4.9,
    "shipping": 5.99,
    "currency": "USD",
    "coupon": "SUMMER_SALE",
    "items": [
      {
        "item_id": "SKU_12345",
        "item_name": "Stan and Friends Tee",
        "affiliation": "Google Merchandise Store",
        "coupon": "SUMMER_FUN",
        "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": "ChIJIQBpAG2ahYAR_6128GcTUEo",
        "price": 10.01,
        "quantity": 3
      }
    ]
  }