How to access postgresql.conf file of postgresql deployment on Heroku

I have a Django app hosted on Heroku, with a postgresql DB, on a Standard 0 plan. I want to access and read the postgresql.conf file for this particular app (to ascertain/edit the settings). Can anyone guide me how to do that?

Note: I can't do that via the Heroku dashboard, and I don't know how to access the app's file structure over the Ubuntu commandline.