Viewing IIS hosted site on other devices on my network

At Hotel we have IIS web server, here is online booking system. We have Global IP address Like this: 31.111.233.134 We bought domain like this: reservation***.com

reservation***.com DNS is our global IP: 31.111.233.134.

How can I make accessible reservation***.com from our local network?

Firewall Rule I was added, but it doesn't working.