Can you reach the dockercontainer? i have used docker only once (without any Proxy settings )but i had to specify which ports from inside go to which on the outside, something like: “docker run --name docker-nginx -p 80:80 nginx” https://www.digitalocean.com/community/tutorials/how-to-run-nginx-in-a-docker-container-on-ubuntu-22-04

You don’t need a Own Domain, you can use a dynamic-dns-service to reach your server from everywhere, even if your ISP changes your ip. I use dedyn.io. (its free) here is a turtorial: https://desec.readthedocs.io/en/latest/dyndns/configure.html