Hej,
like said before, its not recommended to expose the ORPort. The forum link (yes, it's me) only enables IPv6 for outgoing connections from the container and does not expose any ORPorts to the outside. 2001:db8:1::/64 is "IPv6 prefix for documentation purpose", so think of it like 192.168.0.0/16 which is not routed on the internet. Only exposed port is 127.0.0.1:15000:15000 and this is only exposed locally on the docker host to connect the web-server to it. (see https://docs.docker.com/get-started/docker-concepts/running-containers/publi... for example)
Best regards, atari