paperless-ng accessible on external domain and via internal IP

[peterge1998]

PAPERLESS_URL=

PAPERLESS_CSRF_TRUSTED_ORIGINS=

PAPERLESS_ALLOWED_HOSTS=

PAPERLESS_CORS_ALLOWED_HOSTS=

I dont know how to set these variables properly. I want to have https://paperless.domain.de working, but it just gives a CSRF error when PAPERLESS_URL is not set.
When i set PAPERLESS_URL to https://paperless.domain.de, the webinterface is working but the database connection to localhost is not working.
https://paperless.domain.de/ is not working at all.

How do i need to set these 3 vars to get it working in my situation?
I want to reach it via https://paperless.domain.de with http auth and from internal_ip:port.