If you're being redirected to "localhost", that means you might not be using the private network IP address and port number of the host computer (e.g.,
192.168.1.1:9191) if on the same network, or its public IP address and port if on a different network (e.g.,
On Windows it's also important to make sure that there's an exception in Windows firewall for IIS for port
9191, as well as unblocking port
9191 in any other firewall or router between you and the host computer (though you wouldn't even get the localhost page if these were the case, unless you were viewing browser cache somehow).
Lastly, since you're able to reach the content on the same computer, you likely already changed the port of IIS to serve your site on port
9191. If not, here's how: Microsoft Support - How to change the TCP port for IIS services.