Do you have an example of how this works with another tool/language?

I don't know if I understood it correctly but maybe you could:

- Upload your notebook to Github, then create a url with Binder (part of the jupyter ecosystem) directly to an editing/fiddling playground: https://mybinder.org/

- If by user-local you mean on their own machine, they can clone your repo and run their own jupyterlab to fiddle

- If everything should stay on your own computer/server, you could share a link to your own jupyterlab and collaborate with others in real-time: https://jupyterlab-realtime-collaboration.readthedocs.io/en/... (doing this securely might be a bit of a hassle)