404 Error when serving app on binder type server

I am trying to host panel dashboards on research Jupyter Hub, which I do not have admin privileges to. I am trying to get as close as possible to the cause and solution of 404 error when hitting the panel icon

import panel as pn

pn.extension()
pn.panel("Hello Notebook World").servable()

My other functional NBs (locally, on GColab or mybinder) lead to the same 404, which gets triggered immediately, so quite sure no python code gets run.

When I serve from the command line, I am pointed to localhost, which is probably the problem.

$$$$ panel serve Untitled.ipynb --dev
2025-05-15 15:56:33,691 Starting Bokeh server version 3.7.3 (running on Tornado 6.4.2)
2025-05-15 15:56:33,692 User authentication hooks NOT provided (default user enabled)
2025-05-15 15:56:33,694 Bokeh app running at: http://localhost:5006/Untitled
2025-05-15 15:56:33,694 Starting Bokeh server with process id: 7274

Does anyone know how to fix that. Am I missing environment.yml or something? Any suggestions what could I try to investigate further? Thank you very much

panel: 1.6.3
python: 3.10.17
conda: 23.3.1