In Visual Studio Code, when I start the Python Interactive Window (by calling "Run Selection/Line in Python Interactive Window" command, for example), Jupyter server starts in the background. In that window, I can restart the kernel, but I can not find a way to stop the server. How can it be stopped? Simply closing the interactive window only disconnects from the server, but does not stop it.
There is no extra function build in VSCode. But you can manage it regularly from the terminal. You can stop it using jupyter-notebook stop.
Other ways are mentioned here as well: How to close IPython Notebook properly?