Is it possible to configure the VPN appliance to prevent connections from outside the US? Example, I dont a hacker in Russian to be able to connect to the VPN appliance with a compromised account. Is there some sort of Geo Restrict option?
I do not know other way in PCS, besides configuring manually network ranges in
User Realms > Desktop > Authentication Policy >Source IP
But, if someone wants to connect to your server with a compromised account, She/he can create a VM in some cloud provider and use it "attack" you.
You can block it with a external firewall that uses regions/countries in the rules. But as @flipPipe said, a vm could be created in a cloud provider of your region and the connection won't be blocked.