Create 3rd input text for Jupyterlab container establishment

Current the default login page users need to type username and password.
But I would like them to type additional address information in the 3rd block to auto-download datasets users type after the establishment of containers.

Is there an easy way to do this?

I think you’ll need to write a custom authenticator that overrides the default login form with your own version, and add the backend code to store the extra form field.