Required function within an if statement in Helm3

I'd like to know how can I declare a particular values entry as within an using .

{{ required "Value of [varTest] variable is required" .Values.varTest }}

{{- if ne (.Values.varTest | lower | quote) "some_value" }}
apiVersion: batch/v1
kind: CronJob
metadata:
  name: event-chronjob
  namespace: tests-ns
spec:
  schedule: "*/2 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
            - name: event
              image:  some-image:latest
{{- end }}

varTest: ""

When I execute the command I get the following error: