Lunch Notebook with firefox browser arguments

I would like to launch Notebook with firefox and a separate profile

c.NotebookApp.browser = 'firefox --no-remote -P Jupyter'
in config file does not work

Thanks
Murray

Start by tracing how the c.NotebookApp.browser configuration is parsed and used when launching Firefox, then reproduce the command with the --no-remote and -P Jupyter arguments. Done means Notebook launches Firefox with the requested separate profile; the payload does not name a source file or test.

Written by the indexing model from the issue text.