GCP, Nginx-Ingress: Network Endpoint Groups(NEG) not getting created for shared network

Question

I am working on GCP with Nginx Ingress to create Network Endpoint Groups for a shared network. Unfortunately, it's not working for me. I also tried the suggestions mentioned here: Network Endpoint Groups on GKE using shared VPC

My nginx ingress code:

    service:
      annotations:
        cloud.google.com/neg: '{"exposed_ports": {
          "80":{"name": "neg-http-ingress-v2"},
          "443":{"name":"neg-https-ingress-v2"}
        }}'
        cloud.google.com/load-balancer-type: "Internal"
      loadBalancerIP: 10.68.37.123

There are no NEG's getting created. Is there any permission required or any extra steps to follow.

What am I missing?

Thank you. :-)