Click on "Home" and then (on the landing page) on "Apply Now" button in the "Sign Up for using JupyterLab". This should open your default email client with a stub email to the Coordinator. Provide there your name, affiliation, and explain briefly, why do you need to use the GeoML JupyterLab service.
In the landing page, simply click on any button named with "Start...". The app launches in Voila and will ask for further inputs, if needed. When finished, do not forget to close the app properly in order to release the computing resources for other users.
This functionality is currently under construction.