How do I add extra ports to the Helm values.yaml file?

I’m trying to add additional ports in the extraPorts section, but keep getting a converting YAML to JSON error. ...... /templates/service-http.yaml: error converting YAML to JSON: yaml: line 24: could not find expected ':' I’ve tried extraPorts: "8080" and extraPorts: 8080 without any success.

Values file:

It looks like an open issue in GitHub.