Ecommerce with gtag.js

If you use gtag.js as your Google Analytics tag and you have Ecommerce reporting enabled, you can measure ecommerce transactions.

To measure a transaction, send a purchase event with the items in the transaction. For example:

gtag('event', 'purchase', {
  "transaction_id": "24.031608523954162",
  "affiliation": "Google online store",
  "value": 23.07,
  "currency": "USD",
  "tax": 1.24,
  "shipping": 0,
  "items": [
    {
      "id": "P12345",
      "name": "Android Warhol T-Shirt",
      "list_name": "Search Results",
      "brand": "Google",
      "category": "Apparel/T-Shirts",
      "variant": "Black",
      "list_position": 1,
      "quantity": 2,
      "price": "2.0"
    },
    {
      "id": "P67890",
      "name": "Flame challenge TShirt",
      "list_name": "Search Results",
      "brand": "MyBrand",
      "category": "Apparel/T-Shirts",
      "variant": "Red",
      "list_position": 2,
      "quantity": 1,
      "price": "3.0"
    }
  ]
});