To make everyone able to see your website, you need to port forward your website (if you have port forwared your server, you will also need to do this) .
There are tons of tutorials on how to portforward something (use google !) but there are some specific config to do.
(I know that @Falk created a plugin called Volt that does same but this plugin works in a completly different way (that make a lot less laggy and a lot less heavier in space !) and it's fully coded by myself in PHP7)