I tried rewrite send_message_on_dag_fail like only with context as input, now it works.

I don't know why, cause then I tries work with context in task with context (not **kwargs) I've failed.

Any ideas why it works this way?

def send_message_on_dag_fail(context):
    log = context['ti'].log
    log.error('DAG FINISHED WITH ERROR __________________') # this error text easier to find

    task_id = context['ti'].task_id
    dag_id = context['dag'].dag_id
    message = f"Task {task_id} from Dag {dag_id} failed."
    log.error(message)
    send_msg(bot_token, chat_id, message, 'message')