Get value from user input and pass it to custom actions

Hi, I’m trying to get value from user input and pass it to my custom actions. How can I check the value is passed wrong or right?. This is my code nlu.yml :

- intent: confirm
    examples: |
      - [cosplay](hashtag) nha
      - Hashtag là [cosplay](hashtag)
      - Từ khóa là [cosplay](hashtag)
      - hashtag anh muốn tìm là [cosplay](hashtag)
      - Từ khóa cần tìm kiếm là [cosplay](hashtag)
      - Anh muốn tìm về [cosplay](hashtag)

domain.yml :

  - hashtag
    type: text
    influence_conversation: true
      - type: from_entity
        entity: hashtag

stories.yml :

- story: ask trending by hashtag
      - intent: ask_for_tiktok_trending_by_hashtag
      - action: utter_confirm
      - intent: confirm
          - hashtag
      - slot_was_set:
          - hashtag: hashtag
      - action: action_trending_by_hashtag

and my action:

class ActionTrendingByHashTag(Action):

    def name(self) -> Text:
        return "action_trending_by_hashtag"

    def run(self, dispatcher: CollectingDispatcher,
            tracker: Tracker,
            domain: Dict[Text, Any]) -> List[Dict[Text, Any]]:

        hashtag = tracker.get_slot("hashtag")
        result = get_tiktok_trending_by_hashtag(hashtag)
        for video in result:
            dispatcher.utter_message(text=video['title'], image=video['cover'])

        return []

I pass the value to other function (get_tiktok_trending_by_hashtag) to get data. But the received data is not like what I expect. Did I make something wrong? Thanks for you help.