How to force to work through port without IP?

Question

Domain name market

I launched node.js on the VPS, attached the domain, I run the application, but it does not work through the domain:
smilerado.com:3333
but it works like this:
109.234.37.230:3333 The

domain is already attached to the server, I checked the functionality like this:
smilerado.com/public
what could be the problem?

As I see it, there is not enough memory ... will I have to increase it?

Answer 1

More than enough memory. Google about memory management in linux.
After starting, do netstat -apn | grep 3333
View iptables rules: iptables -L --verbose
From machine local nmap -Pn -p 3333 smilerado.com

Answer 2

Alternatively, the application has crashed, and what opens at 109.234.37.230:3333 is from the browser cache.

Answer 3

Does the server itself know about the name-IP mapping?