Unable to upload documents via API/Python

[MagTheRose]

Hi,
I'm trying to upload documents to the vector store via API and python script; neither direct upload to /api/v1/document-store/upsert/{store_id}, nor upload to a corresponding chatflow via /api/v1/vector/upsert/{store_id} works.

API-Key and store_id are correct, as I can list documents I uploaded manually, but I can't upload new documents. Whereas for the document_store I get the flowise-page as response, using the chatflow I get a more promising result:
[200] {"numAdded":0,"numDeleted":0,"numUpdated":0,"numSkipped":0,"totalKeys":0,"addedDocs":[]}

The chatflow itself is functional as I can manually upload a document in the file-upload-node; the API triggers the correct chatflow as on qdrant I see the correct generated (empty) collection, which is not used anywhere else.

I guess, I'm doing something wrong with my source file appending?

Minimal example (python) as see below:

python-minimal.txt