Retrieve submitted files // several ways tried, non succeded

I try to find a suitable way to retrieve files uploaded via forms.
To my knowledge there is no (documented) way to pull a file via the Mautic API.

I currently set it up the following way and failed:

  1. get a system web hook for form submission (as the web hook from the form is missing important submission data)
  2. retrieve the submission ID and file name from the web hook
  3. generate the URL for the file (which is the Mautic URL + “/forms/results/file/XX/file”, where XX is the submission ID)
  4. generate an https request with basic authorization in the header

However, I always get an 403 in response (cURL confirmed this as well).

So is the authentication always based on cookie? I can’t authorize an HTTP request within the header of the request?

Is there any other way I didn’t see?