Hi @Oleksii Petrokhalko, thanks for your question!
If you issue a GET call to the /api/v1/search/query endpoint, you will be returned a field called src that will be present for any attachments in the Card. The contents of that field should look like this:
To download the file, you’ll need to call it as an API endpoint with the GET method, still using your same Guru API credentials. Let me know if this gets you what you need 👍