The SlackAPIFileOperator is not straight forward and it might be better to add an example DAG to demonstrate the usage.

airflow/providers/slack/operators/slack.py
self,
        *,
        slack_conn_id: Optional[str] = None,
        token: Optional[str] = None,
        method: Optional[str] = None,
        api_params: Optional[Dict] = None,
        **kwargs,
    ) -> None:
        super().__init__(**kwargs)
        self.token = token  
        self.slack_conn_id = slack_conn_id  
        self.method = method
        self.api_params = api_params
    def construct_api_call_params(self) -> Any: