How make web server running in virtualbox viewable externally (outside my local network)?

I have a LAMP setup in Ubuntu in VirtualBox. I am able to view the website on any of my computers (and mobile devices) on my local network by going to (the address I gave it) in a web browser. However, if I try to view it externally by going to my external ip address, nothing shows up. What things do I need to do/check to make it so it can be viewed externally?

Setup the router which interfaces with the rest of the world to forward
traffic from TCP 80 to your VM’s IP address. This is usually available
under something like ‘Port Forwarding’ in the router’s UI.

Good luck.

Thanks, I’ll give that a try!