single-user logs

[platreides720]

I am trying to find the logs for a single user.  I entered the following command:  journalctl -u jupyter-<username> 

but I get back "  ---No entries--" 

I used the username from the admin list in Jupyterhub.  I have set the config file to save general JupyterHub logs in /var/log/jupyter.log.  But I need the logs for a specific user, due to server spawn issues.