mTLS per Kubernetes Ingress

I would like to use traefik for exposing both internal and external services. The internal ones would require client certificate verification (mTLS) while the external services will have letsencrypt certificates. I have the letsencrypt certs setup and working. I was wonder how I can define mTLS for the ingresses that expose internal services.

nginx-ingress:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    # Enable client certificate authentication
    nginx.ingress.kubernetes.io/auth-tls-verify-client: "on"
    # Create the secret containing the trusted ca certificates
    nginx.ingress.kubernetes.io/auth-tls-secret: "default/ca-secret"
    # Specify the verification depth in the client certificates chain
    nginx.ingress.kubernetes.io/auth-tls-verify-depth: "1"
    # Specify an error page to be redirected to verification errors
    nginx.ingress.kubernetes.io/auth-tls-error-page: "http://www.mysite.com/error-cert.html"
    # Specify if certificates are passed to upstream server
    nginx.ingress.kubernetes.io/auth-tls-pass-certificate-to-upstream: "true"
  name: nginx-test
  namespace: default
spec:
  rules:
  - host: mydomain.com
    http:
      paths:
      - backend:
          serviceName: http-svc
          servicePort: 80
        path: /
  tls:
  - hosts:
    - mydomain.com
    secretName: tls-secret