How to successfully run a plugin in the local mode?

I am trying to build a Traefik plugin and test it in local mode based on GitHub - traefik/plugindemo: A Traefik demo plugin.

Right now this plugin does nothing and just return "Hello".

Here is my file structure:

In the traefik/plugins-local/src/github.com/Hongbo-Miao/traefik-plugin-disable-graphql-introspection folder, I have:

.traefik.yml

entryPoints:
  graphql-server-entrypoint:
    address: :9000
api:
  insecure: true
  dashboard: true
providers:
  file:
    filename: dynamic_conf.yaml
log:
  level: DEBUG
experimental:
  localPlugins:
    traefik-plugin-disable-graphql-introspection:
      modulename: github.com/Hongbo-Miao/traefik-plugin-disable-graphql-introspection

go.mod

module github.com/Hongbo-Miao/traefik-plugin-disable-graphql-introspection

go 1.17

main.go

package main

import (
	"context"
	"net/http"
)

// Config the plugin configuration.
type Config struct{}

// CreateConfig creates the default plugin configuration.
func CreateConfig() *Config {
	return &Config{}
}

// DisableGraphQLIntrospection a DisableGraphQLIntrospection plugin.
type DisableGraphQLIntrospection struct {
	next http.Handler
	name string
}

// New created a new DisableGraphQLIntrospection plugin.
func New(ctx context.Context, next http.Handler, config *Config, name string) (http.Handler, error) {
	return &DisableGraphQLIntrospection{
		next: next,
		name: name,
	}, nil
}

func (a *DisableGraphQLIntrospection) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
	rw.Write([]byte("hello"))
}

In the root folder, I have

traefik.yaml

entryPoints:
  graphql-server-entrypoint:
    address: :9000
api:
  insecure: true
  dashboard: true
providers:
  file:
    filename: dynamic_conf.yaml
log:
  level: DEBUG
experimental:
  localPlugins:
    traefik-plugin-disable-graphql-introspection:
      modulename: github.com/Hongbo-Miao/traefik-plugin-disable-graphql-introspection

dynamic_conf.yaml

http:
  routers:
    graphql-server-entrypoint:
      service: graphql-server-service
      entrypoints:
        - graphql-server-entrypoint
      rule: Host(`localhost`)
      middlewares:
        - my-traefik-plugin-disable-graphql-introspection
  services:
    graphql-server-service:
      loadBalancer:
        servers:
          - url: http://localhost:5000/
  middlewares:
    my-traefik-plugin-disable-graphql-introspection:
      plugin:
        traefik-plugin-disable-graphql-introspection:
          headers:
            Foo: Bar

I have a GraphQL sever running at http://localhost:5000

I want it go through Taefik and expose by http://localhost:9000

However, when I run

traefik --configfile=traefik.yaml

in the root folder, I got error

traefik.go:79: command traefik error: failed to eval New: 1:28: undefined: traefik_plugin_disable_graphql_introspection 119

Traefik plugins are executed on the fly by Yaegi, an embedded Go interpreter.

The error seems threw by Yaegi, however, I have no clue how to debug.

Any guide would be appreciate!