how can i set public ip in LAN to use web proxy?

I want to set public ip for my local net which will use web proxy. But now problem is when i redirect the tcp-80 traffic to proxy port then it says the routers WAN side ip is accessing the web. how can i set it that the web server will detect my client ip not my server WAN ip? I have not done any source NAT or destination NAT for that public ip.

A proxy takes a client request and makes the request to the web server on behalf of the client. If the web server were to see the client IP address, it would send traffic back to the client and not to the proxy.