[Question] Istio+ AWS ALB + AWS EKS

Hi Guys,
I have a question on how to integrate Istio Ingress Gateway services like Prometheus, Grafana via AWS ALB. I made the Istio Ingress Gateway port type to NodePort instead of LoadBalancer(which is default by type).
istio-ingressgateway NodePort xx.xx.xx.xx 15020:30768/TCP,80:31380/TCP,443:31390/TCP,31400:31400/TCP,15029:31535/TCP,15030:31703/TCP,15031:32626/TCP,15032:30917/TCP,15443:30107/TCP

I tried to add the target group in ALB where I mentioned HTTP port as ‘31703’ for prometheus and mentioned a path ‘/graph’ in the rule from which port forward to target group worker instances port(31703).

Hitting my domainurl/path is not loading the prometheus service(502 Bad Gateway)

Do we need to create Virtual service, Gateway, destination rule for these services(prometheus and Grafana) in order to make the above one work or am i missing something?

Appreciate help on this to resolve the problem.