Unable to access dashboard, always show 404 page not found,how to fix it ?

Binary file I use on mac with arm64.

start command : traefik --configFile traefik.sample.yml

traefik.sample.yml

global:
  checkNewVersion: true
entryPoints:
  web:
    address: :80
  websecure:
    address: :443

api:
  dashboard: true
  insecure: true
  debug: true

providers:
  file:
    watch: true
    filename: dynamic_conf.yaml

log:
  level: DEBUG
  filePath: traefik.log

accessLog:
  filePath: access.log


dynamic_conf.yaml

http:
  services:
    app:
      loadBalancer:
        servers:
          - url: "http://127.0.0.1:8081"
  routers:
    traefik_dashboard:
      rule: "Host(`traefik.example.com`)"
      entrypoints: web
      service: "api@internal"
    app:
      rule: "PathPrefix(`/app`)"
      service: app


then , aceess http://traefik.example.com:8080/dashboard always 404 page not found.

Need help, can you tell me which step went wrong?

Have you tried http://traefik.example.com:8080/dashboard/ ?

https://doc.traefik.io/traefik/operations/dashboard/#the-dashboard

:warning: The trailing slash / in /dashboard/ is mandatory