kubectl convert doesn't do its job

[virtualistic]

https://github.com/jamesbuckett/ckad-questions/blob/main/05-ckad-observability-maintenance.md#05-06-convert-manifests-between-different-api-versions
The command kubectl-convert -f ~/ckad/06-04-beta-ingress.yml --output-version networking.k8s.io/v1
give us this output:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
  creationTimestamp: null
  name: my-ingress
spec:
  rules:
  - http:
      paths:
      - backend: {}
        path: /
        pathType: Prefix
status:
  loadBalancer: {}

but applying it shows an error:

The Ingress "my-ingress" is invalid: spec.rules[0].http.paths[0].backend: Invalid value: "": resource or service backend is required

So you need to copy/paste from the ingress example the service part so it looks like this:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
  creationTimestamp: null
  name: my-ingress
spec:
  rules:
  - http:
      paths:
      - path: / 
        pathType: Prefix
        backend:
          service:
            name: my-service 
            port:
              number: 8080 
status:
  loadBalancer: {}