Cannot run front after fresh install


I try install by follow this guide

everything is fine. but i cannot enter the website.
The message is

This site can’t be reached

xx.xx.xx.xx refused to connect.

I install on Ubuntu 18.04.3 LTS
with port 3000 is already open and can access.

I also try to install by docker follow this
but cannot. By docker, it seems like the port does not mapped properly. ( not show what is the access port )