Hi @StefanGMBG debugging python plugin is not possible in Cinema 4D R25 since debugpy previously known as ptvsd hardcoded the type of the files so you can debug only .py file.
However since S26 we released a Visual Studio Code Extension that work with a Cinema 4D Plugin. And this extension once correctly configured as shown in Cinema 4D Connector - Documentation let you loads, runs, and debugs Cinema 4D scripts and plugins from VS Code.
Cheers,
Maxime.