POST
    /item_images
  
  curl \
 --request POST 'https://stg.getfoundation.com/api/external/v1/item_images' \
 --header "X-API-Key: $API_KEY" \
 --header "Content-Type: multipart/form-data" \
 --form 'item_image={"item_id":"string","sort_order":1,"file":"@file"}'
    
        Response examples (201)
  
  {
  "id": "9aa62446-c3b0-42f5-8027-3648daed9d73",
  "item_id": "string",
  "sort_order": 1,
  "url": "https://example.com",
  "created_at": "2025-05-04T09:42:00Z",
  "updated_at": "2025-05-04T09:42:00Z"
}