VPN (or other) Tunnel.

That's the objective answer. There's no mystery here. That's exactly how you get what you want and it's not too hard. Not trying to dunk on you or anyone one but this is an easily solved problem, and I think I want to highlight it like this to make sure everyone understands.

Anything web/internet/network service thing, you can add this on. This composability is important to remember in software, this even goes back to "The Unix Way" type stuff.