how to edit annotations of pod with non-alphanumeric characters using kubectl

I have a pod which I want to insert the following annotation for:

annotationexample: |
      [
        {
          "a": "b",
          "c": "d",
          "e": [
            "f"
          ]
        }
      ]

When I try to apply this using kubectl annotate --overwrite I get an error saying name part must consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character. The [, ], { and } characters are causing issues, but I have previously been able to apply the annotation through a helm chart. But I am seeking a solution through just using kubectl to only edit annotations. I don't want to create a new pod from a yaml file (kubectl apply -f) as then extra fields are added.

It sounds like you have an error in your command line. If you want to set that annotation on a resource, you would run a command like this:

kubectl annotate pod/example annotationexample='[
  {
    "a": "b",
    "c": "d",
    "e": [
      "f"
    ]
  }
]
'

That results in:

$ kubectl get pod example -o yaml
apiVersion: v1
kind: Pod
metadata:
  annotations:
    annotationexample: |
      [
        {
          "a": "b",
          "c": "d",
          "e": [
            "f"
          ]
        }
      ]
.
.
.