You have newly created and droplet and installed nginx, if i understand you.

First check with below command you web server is listening on port 80.

netstat -tunlp|grep 80

If you see the output it means web server is listening on the default port.

please check the port no 80 is open the outside world or not.

iptables -L -n

This will show all the firewall rules as defined on your system. You can post that, but, generally, if you’re not allowing everything on the INPUT chain, you probably will need to explicitly allow traffic on the port in question:

iptables -A INPUT -p tcp -m tcp –dport 80 -j ACCEPT

iptables-save | sudo tee /etc/sysconfig/iptables

service iptables restart

Hope it will help you.

If you use ufw (which you probably do if you’re using the DO Droplet), I wrote up a fix at https://robertlawson.net/making-the-digital-ocean-dokku-one-click-app-work-without-a-vhost/