How to implement an intermediate server?

Question

linux

Hello, I now have such a chain:
Domain -> Cloudflare -> Main server

How can I add another server to this chain, through which absolutely all network requests from the main server will pass, and requests that will be sent to the main (API that domain, but it works by ip for example), they also went through the intermediate one, so that its ip would only see the intermediate one?

You need to get it like this:
Domain -> Cloudflare -> Intermediate server -> Main server

Thank you!

Answer 1

Well, VPN solves this problem...