I‘m not sure you understand how a vpn works. It usually connects to the outermost part of a network (the router in my case) and then enters through there. The vpn port is always open and thats why I asked since you said thats not the case. (Incase that comes up: there are setups where another port is used for „knocking“ and opens up the entry port. Still one port has to be open to receive anything)
Also, you have no reason to talk down to me. We might have had a misunderstanding here, idk. I‘m just asking to find out what you meant.