Are there any free dedicated server hosting sites or programs?

If you have a reasonably fast internet connection you can host it one one of your own computers..

You need another copy of the game, set to run as the server - or just use the one you play, on your normal machine, if that can be set to act as both server and client.

Then set your router to "port forward" the specific internet ports used by that game, to the machine that is running the server. See your router's instructions for port forward setup (sometimes listed as "Games and applications" or similar).

Finally, get a free "Dynamic DNS" account and create a name for your server to be found by others online.

This one works well: https://www.changeip.com/dns.php

eg. you would end up with yourservername.zyns.com or something along those lines.

You need to install the IP updater tool on the server, or your router may have a dynamic DNS updater built in.

That just checks your public IP address every few minutes and the DNS server gets updated to match after any change, so anyone using your server name always gets directed to the proper public IP address for you game server.

The router port forward then sends it to the correct computer within your LAN.

Edit - just found a guide for that specific game, here:

https://steamcommunity.com/app/376210/discussions/...

It's not 100% accurate but a guide; eg. your subnet mask is likely 255.255.255.0 and with most present routers, individual PCs are identified by their MAC address so you don't need to change to a static IP when setting up port forwarding.

(And it should never be in the range the router uses for DHCP if you do use a static address...)