Cannot Setup egress gateway with SNI proxy

Hello, following the documentation:https://istio.io/docs/tasks/traffic-management/egress/wildcard-egress-hosts/#setup-egress-gateway-with-sni-proxy to configure egress gateway using SNI proxy

I am unable to generate istio-egressgateway-with-sni-proxy.yaml.

I had to make changes to the yaml snippet provided, still I get this error: could not unmarshal the overlay file: unknown field “istio-ingressgateway” in v1alpha2.GatewayFeatureSpec

I used the below yaml

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: istio-egressgateway-sni
spec:
gateways:
enabled: true
istio-ingressgateway:
enabled: false
istio-egressgateway:
enabled: false
istio-egressgateway-with-sni-proxy:
enabled: true
labels:
app: istio-egressgateway-with-sni-proxy
istio: egressgateway-with-sni-proxy
replicaCount: 1
autoscaleMin: 1
autoscaleMax: 5
cpu:
targetAverageUtilization: 80
serviceAnnotations: {}
type: ClusterIP
ports:
- port: 443
name: https
secretVolumes:
- name: egressgateway-certs
secretName: istio-egressgateway-certs
mountPath: /etc/istio/egressgateway-certs
- name: egressgateway-ca-certs
secretName: istio-egressgateway-ca-certs
mountPath: /etc/istio/egressgateway-ca-certs
configVolumes:
- name: sni-proxy-config
configMapName: egress-sni-proxy-configmap
additionalContainers:
- name: sni-proxy
image: nginx
volumeMounts:
- name: sni-proxy-config
mountPath: /etc/nginx
readOnly: true