Traefik proxy an external webserver


I have a Traefik2 installation within Kuberntetes, proprerly prtoxying different internal services.
I'd like to also use Traefik to proxy a couple of external webservers (external in that they're not kubernetes services) with ingressroute.

I tried the endpoints+service way and some others, without any success...

Is there a clear guide to follow with some examples?

Thank you verry much