Cannot get python scripts with postMessage to work

I followed the instructions to build Collabora Online on Ubuntu, I went to https://localhost:9980/loleaflet/dist/framed.doc.html?file_path=/home/michael/Documents/collabora-online/test/data/hello-world.ods and all postMessages are working except the CallPythonScript ones.

Am I missing something?

Have you done the following step, as written in the docs?

Additional security is provided by not enabling the Python script provider by default. You need to explicitly install the collaboraofficebasis6.x-python-script-provider and collaboraofficebasis6.x-pyuno packages (replace x with the respective version number) to enable Python scripts.

Yes I did, forgot to mention it.

michael@ubuntu:/opt/collaboraoffice6.4/share/Scripts/python$ ls   pythonSamples