Kubernetes apiVersion: networking.k8s.io/v1 Issue with 'Ingress'

Wanted your guidance on an issue while executing a Kubernetes YAML file. My kubectl version is as follows:

    Client Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.0", GitCommit:"af46c47ce925f4c4ad5cc8d1fca46c7b77d13b38", GitTreeState:"clean", BuildDate:"2020-12-08T17:59:43Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"windows/amd64"}
    Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.14", GitCommit:"89182bdd065fbcaffefec691908a739d161efc03", GitTreeState:"clean", BuildDate:"2020-12-18T12:02:35Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}

This is the latest version downloaded from the Kubernetes site https://kubernetes.io/docs/tasks/tools/install-kubectl/#install-kubectl-on-windows

The YAML has apiVersion: networking.k8s.io/v1 kind: Ingress and the error on running the YAML is

    no matches for kind "Ingress" in version "networking.k8s.io/v1"

Kubernetes issue https://github.com/kubernetes/kubernetes/issues/90077 mentions that

  networking.k8s.io/v1beta1 == 1.14 to 1.18
  networking.k8s.io/v1 = 1.19+

So I guess it should be working right?

I have changed the API Version to

apiVersion: extensions/v1beta1 or
apiVersion: networking.k8s.io/v1beta1

but fail in another section of the YAML

backend:
  service:
    name: {{ template "fullname" $ }}-srv
     port:
       number: 80

with the error

error validating data: ValidationError(Ingress.spec.rules[0].http.paths[0].backend): unknown field "service" in io.k8s.api.extensions.v1beta1.IngressBackend

I am informed that the same YAML works on macOS with the same kubectl version (I do not have access to verify that though). But any thoughts on where I could be going wrong?

Thanks, Prabal

backend:
  serviceName: {{ template "fullname" $ }}-srv
  servicePort: 80

kubectl explain --api-version=networking.k8s.io/v1beta1 ingress.spec.rules.http.paths.backend