Terminate TLS and forward new HTTPS request

Hi all,
I have a bit an unusual request. From my browser I call a service with HTTPS. Traefik (used as Ingress into my Kubernetes) terminates the TLS. So my user will see a valid Let's Encrypt certificate.

Now my tricky part: Forwarding the request to my service needs to be done through HTTPS. At service side there is a second self signed certificate, which I want to hide from the end user. Of course, the self signed certificate can not be verified.

My definition looks like follows:

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: ingressroute-service
  namespace: default
spec:
  entryPoints:
    - websecure
  routes:
  - match: Host(`myhost.com`)
    kind: Rule
    services:
    - name: service
      port: 8080
  tls:
    certResolver: myresolver

This works. What do I have to do to switch to service with HTTPS and an unsigned certificate?

Is there a middleware configuration within Traefik that I can achieve such? Thanks for any advise.
Wolfram

I just found out by myself and it is soooooo simple:

services:
    - name: service
      port: 8443
      scheme: https

That's it.
Hope this will help others.
Wolfram