If you see this in pink in Section 2.1 of tutorial notebook 01 (Intro to DP0), it is not an error. You can ignore it and keep executing the rest of the notebook.
Patching auth into notebook.base.handlers.IPythonHandler(notebook.base.handlers.AuthenticatedHandler) -> IPythonHandler(jupyterhub.singleuser.mixins.HubAuthenticatedHandler, notebook.base.handlers.AuthenticatedHandler)