Nodejs app how to load domain instead of ip + port

I have an app that I would like to load using a domain name instead of the ip:port. It currently loads find with the ip and port but I can not get it to work with a domain. I have created the subdomain A record and tried a few tutorials. None of which seem to work. These two seemed promising but still did not work for me: https://www.digitalocean.com/community/tutorials/how-to-use-apache-http-server-as-reverse-proxy-using-mod_proxy-extension

https://www.digitalocean.com/community/questions/nodejs-app-loads-in-browser-via-ip-port-but-not-domain-port-dns-set-to-do-servers-in-registrar-account-a-and-cname-are-set-help