lightsail ubuntu, nodejs, express no route -> UFW open port 3000

 Hello, 

I have spent 2 days for reopen node app from github. 

Nothing works after clonning source code from github. 

So, I have been trying many ways to make it work. 

With 2days full time research, I have found that ubuntu firewall blocked all request. 

$> sudo ufw allow 3000:3999/tcp

Now, it works like a charm.