Noob question: Server Setup

Hi there, have not been in the server space for years and I think it is right in front of me, but I have lost my touch...

So I set up my Debian on my virtual server, I have installed docker and I am running the metabase in said docker. I have installed Java and I have set up the dbs. But when I run the docker image on lets say port 12345, I get no answer on ServerIP:12345.

What am I missing.

Appreciate y'alls help and I am sorry, this will be so obvious.
Marko

have you mapped the port 3000 inside the docker container to the host port 12345?