How to work with postgresql in django project?

Question

PostgreSQL

I used to use the standard django + sqlite bundle, and in general it was done on windows. There were no problems with working with the database: I wrote code for myself in models and did not take a steam bath.
Now, having owned ubuntu and configured django + postgresql + nginx + gunicorn, I don’t quite understand how to implement the work of this subd in the project. That is, here I am creating a database in psql through the terminal, riveting signs in it. And, actually, what then? What to do with models.py?
Maybe you could throw in another article so that I understand what to do at all? Or just suggest? Thank you.