oslo.config override gunicorn command line

[Mystic]

I have a flask app that was wrapped by WSGI middleware that is to log for each request. In the custom middleware, I use oslo.config to read from the config file(Not from the CLI parameters, from 'default_config_files'). When starting the app with Gunicorn, it throws the error:

gunicorn: error: unrecognized arguments: -c /etc/cc/server.conf cc_api.socket_io:application
usage: gunicorn [-h] [--config-dir DIR] [--config-file PATH]

I use this gunicorn command to start app:
gunicorn -c /etc/cc/server.conf cc_api.socket_io:application

The usage I used is right? If not, how to use oslo.config?

BTW, I do not want to get config file path from CLI.