如何在Rasa的表单requested_slot函数中使用dispatcher来显示bot消息？

from typing import Any, Text, Dict, List
from rasa_sdk import Action, Tracker
from rasa_sdk.executor import CollectingDispatcher

class DisplayBotMessageAction(Action):
    def name(self) -> Text:
        return "action_display_bot_message"

    def run(self, dispatcher: CollectingDispatcher,
            tracker: Tracker,
            domain: Dict[Text, Any]) -> List[Dict[Text, Any]]:
        # 在这里编写你的逻辑
        # 使用dispatcher发送bot消息
        dispatcher.utter_message(text="这是一个示例bot消息")
        return []

actions:
  - action_display_bot_message

intents:
  - display_bot_message

stories:
  - story: 显示bot消息
    steps:
      - intent: display_bot_message
      - action: action_display_bot_message