curl --request GET \
  --url http://localhost/api/v3/transactions/{transaction}/items

{
  "data": [
    {
      "id": 123,
      "external_id": "<string>",
      "name": "<string>",
      "transaction_id": 123,
      "product_id": 123,
      "product_variant_id": 123,
      "sku": "<string>",
      "variant_external_id": "<string>",
      "is_void": true,
      "quantity": 123,
      "price_current": 123,
      "price_sell": 123,
      "price_original": 123,
      "price_margin": 123,
      "price_tax": 123,
      "is_return": "<string>",
      "discounts": [
        "<unknown>"
      ],
      "department": "<string>",
      "meta": [
        "<unknown>"
      ],
      "product_images": {},
      "order_id": 123,
      "created_at": "<string>",
      "updated_at": "<string>",
      "pivot": {
        "created_at": "<string>",
        "updated_at": "<string>"
      },
      "product_variant": {
        "id": 123,
        "product_id": 123,
        "sku": "<string>",
        "external_id": "<string>",
        "barcode": "<string>",
        "web_url": "<string>",
        "handle": "<string>",
        "title": "<string>",
        "description": "<string>",
        "position": 123,
        "price": 123,
        "price_discounted": 123,
        "price_comparison": 123,
        "price_cost": 123,
        "available_quantity": 123,
        "images": "<string>",
        "meta": [
          "<unknown>"
        ],
        "tags": [
          "<string>"
        ],
        "options": [
          {
            "name": "<string>",
            "value": "<string>",
            "sort_order": 123
          }
        ],
        "created_at": "<string>",
        "updated_at": "<string>"
      },
      "product": {
        "title": "<string>",
        "department": "<string>",
        "brand": "<string>",
        "custom_fields": [
          {
            "name": "<string>",
            "handle": "<string>",
            "namespace": "<string>",
            "value": "<string>",
            "type": "<string>",
            "custom_fieldable_type": "<string>",
            "custom_fieldable": {
              "id": "<string>",
              "external_id": "<string>",
              "profile_id": "<string>",
              "meta": "<string>",
              "total": "<string>",
              "total_original": "<string>",
              "rounding": "<string>",
              "margin": "<string>",
              "is_void": "<string>",
              "transacted_at": "<string>",
              "timezone": "<string>",
              "payments": "<string>",
              "receipt_is_email": "<string>",
              "receipt_ref": "<string>",
              "linked_receipt_ref": "<string>",
              "claimed_at": "<string>",
              "receipt_email": "<string>",
              "currency_id": "<string>",
              "currency_rate": "<string>",
              "currency": "<string>",
              "type": "<string>",
              "status": "<string>",
              "order_number": "<string>",
              "order_id": "<string>",
              "external_order_id": "<string>",
              "created_at": "<string>",
              "updated_at": "<string>"
            },
            "created_at": "<string>",
            "updated_at": "<string>",
            "version": 123,
            "is_index": 123
          }
        ]
      },
      "transaction": {
        "transacted_at": "<string>",
        "receipt_ref": "<string>",
        "external_id": "<string>"
      },
      "list_items": [
        {
          "id": "<string>",
          "product_list_id": "<string>",
          "list": {
            "name": "<string>",
            "handle": "<string>",
            "description": "<string>"
          },
          "created_at": "<string>",
          "updated_at": "<string>",
          "quantity": "<string>",
          "position": "<string>",
          "status": "<string>",
          "meta": "<string>",
          "pivot": {
            "created_at": "<string>",
            "updated_at": "<string>"
          }
        }
      ]
    }
  ]
}