Confussed on how to rewrite the path with Traefikv2

Question

I have a backend Intersystems application at http://internal.domain.com:57772/csp/obj/cpocdashboard.csp which I am trying to proxy to the outside world with https://dash.domain.com using traefik. I'm having a hard time trying to find an example that's easy for a noob to understand. I started out with this, and it's not working.

[http.routers]
  [http.routers.poc_dash-rtr]
      entryPoints = ["https"]
      rule = "Host(`dash.domain.com`)"
      service = "poc_dash-svc"
      middlewares = ["chain-basic-auth"]
      [http.routers.poc_dash-rtr.tls]
        certresolver = "lets-encrypt"
        
[http.services]
  [http.services.poc_dash-svc]
    [http.services.poc_dash-svc.loadBalancer]
      passHostHeader = true
      [[http.services.poc_dash-svc.loadBalancer.servers]]
        url = "http://192.168.170.16:57772/csp/obj/cpocdashboard.csp"

Can someone point me to the redirection and maybe explain a little or point me to a place we it is easily understandable? Thanks for all help