We are receiving the following error when calling GetAlarmClient: "There was no endpoint listening at http://192.168.0.86:22331/Central/AlarmServiceToken that could accept the message". Is there something that we need to start on the server itself?

I have checked with the client and they believe they are forwarding ports 22331 and 22333.

Can you please see this article? It might be helpful for you -

https://developer.milestonesys.com/s/article/Ports-for-alarms-from-Milestone-Event-Server-service