Traefik does not find IP address of nginx-mailcow and hence no certificate is created

I am trying to setup the mailcow behind Traefik proxy. But Traefik is unable to recognize the nginx-mailcow container and does not create a certificate. Does someone know how to fix the problem? I also created an issue on github (in mailcow repository - link below). So far no luck. Any help will be much appreciated. Thanks.

Actually after investing a couple of hours in reading the Traefik documentation I finally spotted the problem. There was slight mistake in assigning the labels to nginx-mailcow service.