curl --request GET \
  --url https://api.example.com/purchases/{purchase_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'x-api-key: <x-api-key>'

{
  "purchase_id": "<string>",
  "date": "<string>",
  "total": "<string>",
  "tax": "<string>",
  "subtotal": "<string>",
  "item_count": 123,
  "items": [
    {
      "item_id": "<string>",
      "price": "<string>",
      "quantity": "<string>",
      "product": {
        "product_id": "<string>",
        "description": "<string>",
        "name": "<string>",
        "upc": "049000028911",
        "brand": "diet-coke"
      }
    }
  ]
}