How to use an ingress gateway to access a gRPC service (MTLS)

Security
1 
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: api-gateway
spec:
  selector:
    istio: ingressgateway
  servers:
  - hosts:
      - "api.httpbin.com"
    port:
      number: 80
      name: grpc
      protocol: GRPC
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: api-rpc
spec:
  hosts:
    - api.httpbin.com
  gateways:
    - api-gateway
  http:
  - match:
    - gateways:
        - api-gateway
      port: 80
    route:
    - destination:
        host: rpc-host-svc
        port:
          number: 80
    timeout: 10s
---
apiVersion: v1
kind: Service
metadata:
  name: rpc-host-svc
  labels:
    run: rpc-host-svc
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8064
  selector:
    app: rpc-host

I want to change to MTLS, but I don’t know how to do this? anyone can help me, thanks?
(istio verison) 1.7.3

2

Hi Jimmy, will this samlpe help in your case? Istio / Secure Gateways