Expose docker container to the Internet

Hello everyone, I’m trying to expose a simple Docker container with nginx image to the Internet.

I’ve configured on the router (fritzbox) the access from DNS noip.com address that re-new every month.
I started the container with nginx and expose port 8080 on my host.
I’ve configured the router to expose port 8080 of my host.

But the docker container still reachable only from inside the network and not reachable from outside?

When i do the mistake?