Authentication Not Working for Traefik Dashboard (v2.1.4)

Hi Folks,

I new to Traefik, i manage to configure latest version of Traefik in my Docker lab, i would like to set authentication for Traefik dashboard but it is not working for me. I am using below docker-compose file, i might be using wrong labels as i am not sure which exact labels to be used to setup authentication. Could you please suggests correct procedure to enable authentication for dashboard ...

version: '3.7'

    # The official v2 Traefik docker image
    image: traefik:v2.1
    # Enables the web UI and tells Traefik to listen to docker
    command: --api.insecure=true --providers.docker --api.dashboard=true --log.level=ERROR --metrics.datadog=true --providers.docker.exposedbydefault=false --metrics.datadog.address=localhost:8125 --metrics.datadog.addentrypointslabels=true --log.format=json --accesslog.format=json --accesslog=true
      # The HTTP port
      - "80:80"
      # The Web UI (enabled by --api.insecure=true)
      - "8080:8080"
      # So that Traefik can listen to the Docker events
      - /var/run/docker.sock:/var/run/docker.sock
      - "traefik.enable: true"
      - "traefik.http.routers.dashboard.rule: Host(``)"
      - "traefik.http.routers.dashboard.rule: PathPrefix(`/dashboard`) || PathPrefix(`/api`)"
      - "traefik.http.routers.dashboard.entrypoints: api"
      - "traefik.http.routers.dashboard.middlewares: auth"
      - "traefik.http.routers.dashboard.service: api@internal"
      - "traefik.http.middlewares.admin-auth.basicauth.users=admin:$$apr1$$x7A0C9gd$$wVN4Ve7H5SLsaMVwH2olO/"


The middleware name (admin-auth) must be the right in the router definition.