How to use specific IP address for Egress traffic using istio

Description

I’d like to control my egress traffic by using specific IP address for outgoing connections. So that I can allow access on external services from kubernetes.

Issue

When I follow this, it’s only working if the pod that is initiating the request has access to the external service. I’d like send the request to the egress gateway pod and the pod should send the origin request to it’s destination. Kind of proxy thing. Is it achievable? If yes, how can I achieve that?