Ask? Sure. Write code that pops up the firewall exclusion message you linked? Waste of time. This should happen automatically anyway but last time I saw this message, that was … Windows 7 probably.
It isn’t enough to open the port on the Windows firewall because practically no user has his machine connected directly to the Internet. There’s almost always a router in-between which performs NAT where port forwarding has to be set up or else there will be no incoming traffic to this machine on your game’s port to begin with. The router may also have a firewall enabled.
You can provide support material for the user to perform the port forwarding and the firewall exclusion but you can expect most not to follow through, and those who do will have trouble with it and likely going to ask you for support.
udp gets autoblocked thanks for trying to help (meaning it needs an firewall exception) and also i am creating lan multiplayer so port forwarding is not gonna help still thoe thanks