objectName [string] [Required]=the name of the object that contains the file.
fieldName [string] [Required]=the name of the field (API name) that contains the file. This field is one of the fields of the objectName object.
RecordId [long] [Required]=the ID of the record from which you want to retrieve the file.
Success Response
Status Code=200 (OK)
Error Response:
Status Code=400 (BadRequest) (in case there is an error in the JSON data sent in the HTTP Post Request body or the object name, API field name in the object or in the Id record is incorrect)