How to understand why the port on Digital Ocean does not work?

Question

Computer networks

Hello.

docker volume create portainer_data
docker run -d -p 8000:8000 -p 9000:9000 --name=portainer --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer

According to the documentation, I installed Portainer locally to manage the docker, everything works fine localhost:9000.
I did the same on Digital Ocean and the webcam does not open on request, http://ipaddress:9000why?
Firewall is not created, in theory everything is allowed.
Of course, I created Firewall rules where I allowed any TCP \ UDP traffic - it didn’t help

. The request just loads for a long time and falls by timeout.
How to detect what exactly is the problem? Who drops the request, and so on.

If you know how you can connect something similar to Docker Dashboard via ssh, then I will be glad to see a link.
My ultimate goal is to manage docker remotely in some kind of interface.

Answer 1

recreating the server - it worked on a clean server -_- Thank you all

Answer 2

show that with firewall
iptables -L -vnx