I am having the same issue when trying to disable a menu item under File menu in jupyterhub. I put the css file under /home/jovyan/.jupyter/custom, but unfortunately there is no --custom-css to use for jupyterhub. I also tried to use the spawner args: --ServerApp.extra_static_paths=[“/home/jovyan/.jupyter/custom”]’ but no good luck. Is there any alternative to disable a menu item for jupyterhub? Thanks.