GRPC request to AKS Cluster through Nginx Ingress

I am trying to make a GRPC request to my service through Nginx Ingress. I enabled tls termination globally, from ingress's configmap. I try to make a request with postman (not only), but it fails.

Service is simple ClusterIP service.

I try to specify host like this 'domain_name/ss:81', but it fails.

Maybe someone has a working example.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: name
  namespace: namespace
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
    nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
    nginx.ingress.kubernetes.io/backend-protocol: "GRPC"
spec:
  rules:
    - host: domain_name
      http:
        paths:
          - path: /ss
            pathType: Prefix
            backend:
              service:
                name: service name
                port:
                  number: 81