kyverno/demo/mutate_patch/policy_patch.yaml

apiVersion : kyverno.io/v1alpha1
kind : Policy
metadata :
  name : policy-endpoints
spec :
  rules:
    - name: pEP
      resource:
        kinds : 
        - Endpoints
        selector:
          matchLabels:
            label : test
      mutate:
        patches:
          # add a new label
          - path: "metadata/labels/isMutate"
            op: add
            value: true
          # replace port 
          - path : "/subsets/0/ports/0/port"
            op : replace
            value: 9663