Project Jupyter is "a project to develop open-source software, open standards, and services for interactive computing across multiple programming languages." (Wikipedia) JupyterLab is their web IDE, while JupyterHub is a server program that spawns JupyterLab instances. We have JupyterHub running at https://hub.exozy.me.
The JupyterLab instances spawned at https://hub.exozy.me do not support installing extensions, because JupyterLab assumes it's running in an environment where it has write access to Python packages, but this isn't the case for distro-installed JupyterLab. (More info at #210)
Instead, you should:
Create and activate a venv
Install JupyterLab in the venv with pip install jupyterlab
Start JupyterLab with jupyter-lab
Forward the port to your computer using SSH (if that's not an option, run jupyter-lab on a 4200-4209 port)
Now you can install extensions!
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