Helm (jinja2): parse error "did not find expected key" at a non-existant further line

Question

This is my first question ever on the internet. I've been helped much by reading other people's fixes but now it's time to humbly ask for help myself.

I get the following error by Helm (helm3 install ist-gw-t1 --dry-run )

Error: INSTALLATION FAILED: YAML parse error on istio-gateways/templates/app-name.yaml: error converting YAML to JSON: yaml: line 40: did not find expected key

However the file is 27 lines long! It used to be longer but I removed the other Kubernetes resources so that I narrow down the area for searching for the issue.

Template file

{{- range .Values.ingressConfiguration.app-name }}
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: "{{ .name }}-tcp-8080"
  namespace: {{ .namespace }}
  labels:
    app: {{ .name }}
    chart: {{ $.Chart.Name }}-{{ $.Chart.Version | replace "+" "_" }}
    release: {{ $.Release.Name }}
    heritage: {{ $.Release.Service }}
spec: 
  hosts: # Is was line 40 before shortening the file. 
  - {{ .fqdn }} 
  gateways: 
  - {{ .name }}
  {{ (.routing).type }}:
  - route:
    - destination:
        port:
          number: {{ (.services).servicePort2 }}
        host: {{ (.services).serviceUrl2 }}
    match:
      port: "8080"
      uri:
        exact: {{ .fqdn }}
{{- end }}

values.yaml

networkPolicies:


ingressConfiguration:
  app-name:
  - namespace: 'namespace'
    name: 'app-name'
    ingressController: 'internal-istio-ingress-gateway' # ? 
    fqdn: '48.characters.long'
    tls: 
      credentialName: 'name-of-the-secret' # ? 
      mode: 'SIMPLE' # ? 
    serviceUrl1: 'foo' # ? 
    servicePort1: '8080'
    routing:
      # Available routing types: http or tls
      # In case of tls routing type selected, the matchingSniHost(resp. rewriteURI/matchingURIs) has(resp. have) to be filled(resp. empty)
      type: http
      rewriteURI: ''
      matchingURIs: ['foo']
      matchingSniHost: []
  - services:
      serviceUrl2: "foo"
      servicePort2: "8080"
  - externalServices: 
      mysql: 'bar'

1. Where does the error come from?
2. Why does Helm still report line 40 as problematic -- even after the shortening of the file.
3. Can you please recommend some Visual Studio Code extention that could have helped me? I have the following slightly relevant but they do not have linting (or I do not know to use it): YAML by Red Hat; amd Kubernetes by Microsoft.