NLB Target Group (EKS pod/application) fails on health checks

Question

I'm trying to expose argocd via loadbalancer svc (internal nlb) for private link (Endpoint Service). However, NLB Target Group for argocd fails on health check. EKS cluster is in private subnets.

apiVersion: v1
kind: Service
metadata:
  name: argocd-server-nlb
  namespace: argocd
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-type: nlb
    service.beta.kubernetes.io/aws-load-balancer-internal: "true"
spec:
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  type: LoadBalancer
  selector:
    app.kubernetes.io/name: argocd-server

I expect that when I exposed argocd via NLB the health check will success.