<p>So as in the title, I would like to add labels to my helms of my already running applications (sonarqube and jenkins from official helm charts).
I don't have templates in them just values.yaml. I am afraid of adding templates, because as I said, application is already running and I just want to add few labels in metadata.</p>

<p>Both charts mentioned in comment under question has a way to define custom labels</p>
<p><a href="https://github.com/jenkinsci/helm-charts/blob/main/charts/jenkins/templates/jenkins-master-deployment.yaml#L42" rel="nofollow noreferrer">https://github.com/jenkinsci/helm-charts/blob/main/charts/jenkins/templates/jenkins-master-deployment.yaml#L42</a></p>
<pre><code>    {{- range $key, $val := .Values.master.podLabels }}
    {{ $key }}: {{ $val | quote }}
    {{- end}}
</code></pre>
<p><a href="https://github.com/Oteemo/charts/blob/master/charts/sonarqube/templates/deployment.yaml#L31" rel="nofollow noreferrer">https://github.com/Oteemo/charts/blob/master/charts/sonarqube/templates/deployment.yaml#L31</a></p>
<pre><code>{{- with .Values.podLabels }}
{{ toYaml . | indent 8 }}
{{- end }}
</code></pre>
<p>So you need something like this in <code>values.yaml</code></p>
<pre><code># Jenkins
master:
  podLabels:
    label1Name: label1Value

# Sonar
podLabels:
  label1Name: label1Value
</code></pre>
