docker image setup with system apache

[exoterws]

Dear Anubis community:
(note the apache documention https://anubis.techaro.lol/docs/admin/environments/apache sometimes refers to 9000 vs 8923, and sometimes 3001 vs
3923, but I'm always using 8923 and 3923 to follow the environmental values here: https://anubis.techaro.lol/docs/admin/installation/#environment-variables

tldr:

• docker image doesn't work for me
• deb does work
• the hop from anubis back to apache seems to be the problem
• probably i don't know how to correctly run the docker image

I've been trying to use the docker image with my system's (Debian) apache. My apologies if you aren't even supposed to do this. This is being done in a VM for testing before i deploy it, so the certs are snakeoil and there's no domain name. Basically I can't get it to work, probably because I lack fundamental knowledge of docker and networking.

I read the Apache setup section of the environments documentation and setup the virtualhost stuff as instructed. When I run the deb version of anubis on the vm, and then access the VM via a browser another computer , the Anubis cat person dutifully appears (briefly) before sending me on to the test website hosted on the VM, so I guess it's working.

But with the docker image, though I pulled the anubis:latest, I can't get it to work. I think I don't even understand how to do the docker run command. If anubis (docker container) is supposed to listen in on 8923 and apache is listening on 3923, what do I have to do to get the anubis in the docker to communicate with the system apache? What environmental variables and port publishing do I need to define for the anubis with docker run -p and -e arguements?
BIND=:8923 ?
what am I supposed to define TARGET as? the default http://localhost:8923 or the gateway IP address (172.17.0.1) visible in docker inspect?

the best i can do with a docker run -p 8923:8923 and the BIND=:8923 argument is that, when I visit the VMs website, the cat person appears but then redirects me to a 502 page.
Here docker logs gives me this each time I try to access.
http: proxy error: dial tcp 172.17.0.1:3923: connect: connection refused"