Traefik v2 Forward to External Host via Docker-Compose

I am new to traefik and followed a tutorial to set up basic services via docker-compse using wildcard certificates. All routing is done via labels (shown below). I think I've started to grasp handling Docker containers with Traefik, with a successful wordpress site and Traefik dashboard running as desired. The configurations are starting to make sense for the most part.

The next thing I wanted to do seemed like it should be easier than what I have so far, but I'm obviously missing something. I have a synology NAS that I would like to access via synology.mydomain. Just a simple forward to my NAS local ip #.#.#.#:5000. The labels for my Traefik container are shown below with what I've tried, but when I start the containers, I get 404 errors both at synology.mydomain and traefik.mydomain (dashboard). The wordpress site still works at www.mydomain. If I comment out all of the ...synology... labels, everything works fine. If I just comment out the services.synology-svc label, everything else works, and the dashboard shows an error: "the service "synology-svc@docker" does not exist" (which makes sense because I'm pointing to it but never define it). I didn't want to paste the whole docker-compose.yml, but if this isn't enough info, I can do that. Any suggestions are greatly appreciated. I fear I may be approaching this from the wrong angle at this point...

Thanks in advance!

      - "traefik.enable=true"
      # HTTP-to-HTTPS Redirect
      - "traefik.http.routers.http-catchall.entrypoints=http"
      - "traefik.http.routers.http-catchall.rule=HostRegexp(`{host:.+}`)"
      - "traefik.http.routers.http-catchall.middlewares=redirect-to-https"
      - "traefik.http.middlewares.redirect-to-https.redirectscheme.scheme=https"
      # HTTP Routers
      - "traefik.http.routers.traefik-rtr.entrypoints=https"
      - "traefik.http.routers.traefik-rtr.rule=Host(`traefik.$DOMAINNAME`)"
      - "traefik.http.routers.traefik-rtr.tls=true"
      - "[0].main=$DOMAINNAME"
      - "[0].sans=*.$DOMAINNAME"
      - "traefik.http.routers.synology-rtr.entrypoints=https"
      - "traefik.http.routers.synology-rtr.rule=Host(`synology.$DOMAINNAME`)"
      - "traefik.http.routers.synology-rtr.tls=true"
      ## Services - API
      - "traefik.http.routers.traefik-rtr.service=api@internal"
      ## Services - Synology
      - "traefik.http.routers.synology-rtr.service=synology-svc"
      - ""
      ## Middlewares
      - "traefik.http.routers.traefik-rtr.middlewares=chain-oauth@file"
      - "traefik.http.routers.synology-rtr.middlewares=chain-no-auth@file"

This is not valid for the docker provider, that assumes that the container the router is attached to is the service.

You need to define this in the file provider and it should work fine.