How to set up a web server through an iPhone ATT Personal Hotspot

​I have a computer with a web server showing images we are creating in a photo shoot. We want our remote client to see them. The computer is attached to a personal hotspot provided by an iPhone which is on the ATT network.​

​When we attach another computer to that hotspot, it can see the web server. However, when we try to connect to it from outside the hotspot's subnet, it is inaccessible. It appears that the phone is acting like my home router does, providing local IP addresses which are not on the internet (the phone's internet address begins with 166.198 while the webserver's begins with 172.20).​

​Is there any way to get this computer accessible from the internet using the ATT hotspot?

​Gary​