curl --request GET \
  --url https://api.sandbox.usenash.com/v1/product/external_identifier/{externalIdentifier}

{
  "id": "<string>",
  "externalIdentifier": "ext_001",
  "name": "Organic Bananas",
  "description": "Fresh organic bananas, perfect for smoothies and baking",
  "imageUrls": [
    "https://example.com/bananas1.jpg",
    "https://example.com/bananas2.jpg"
  ],
  "categories": [
    "Produce",
    "Fruits",
    "Organic"
  ],
  "weight": 0.5,
  "dimensions": {
    "depth": 8,
    "height": 4,
    "width": 12
  },
  "identifiers": [
    {
      "type": "UPC",
      "value": "123456789012"
    }
  ],
  "attributes": [
    "WEIGHTED"
  ],
  "details": {
    "weighted_item_info": {
      "weight_per_item": 0.12,
      "weight_unit": "kg"
    }
  }
}