Push a Django project and Railpack builds it, runs your migrations and serves it with Gunicorn, on a server you own.
Deplo builds with Railpack by default, so a Django project needs no Dockerfile to get started.
Short answers to what comes up before moving a Django app onto your own server.
From the WSGI_APPLICATION setting, or from the RAILPACK_DJANGO_APP_NAME variable when you set it.
Yes. Managed databases live in the same environment and reach the app over the internal network.
In the app's settings, per environment. They are available during the build too, and secret values are write only: nothing reads them back.
Answer three questions and pick a host, or install Deplo on a server you already have. It's free, and leaving is as easy as arriving. What you do with the money you save is your business.