Accessing netPI web UI with REST API

[tad]

Dear Armin,

I created the attached Node-RED flow for Control Panel by referring to the Node-RED flow of the REST API for Portainer as you explained.
I was able to access netPI from Node-RED on a PC.
Thank you very much for your advice.

So, I will only continue to create Node-RED flows to access Control Panel hereafter.
(I will forget an html file anymore.)

And, I have another questions, please.
As far as I study the API for Control Panel using https://editor.swagger.io/, some APIs below mention 'category is used for user access'.
- /get/syslog/files
- /get/syslog/file
- /get/pki/files

Would you please let me know what to enter in 'category'?
I tried to enter '1' or ''(null), netPI responded to the payload as follows:
{ status: "Failed", message: "Permission denied" }

One more question is: there is a menu to enable Docker in Services-> service list.
A user can control 'operating status' and 'autostart' from its Web GUI.
Is it possible to execute them using REST API?

Thank you very much for your support.
Best regards,