You can get your attachment with the request GET Download document attachment by ID.
The sequence of requests should be like this:

  1. GET the list of the documents with Idns; 
    Example: Get Invoices list
  2. Extract all the Idns from the response;
  3. GET every document by Idn; 
    Example: Get Invoice by Idn
  4. Extract all of the attachment Ids;
  5. GET attachment by Id.
    Example: Download document attachment by Id 

Where to find the attachment Id:

Use interface filters in your API request to GET a filtered list of documents via API: 

  • Apply filters in the Precoro interface;
  • Copy a part of the URL;
    Example: ?creator[]=24650&createDate[left_date]=01.04.2021&createDate[right_date]=28.04.2021
  • And paste this part in your request.