code: def send_action(self, recipient_id, action, notification_type=NotificationType.regular):
          
          return self.send_recipient(recipient_id, {
              'sender_action': action
          }, notification_type)
docs: Send typing indicators or send read receipts to the specified recipient.
          https://developers.facebook.com/docs/messenger-platform/send-api-reference/sender-actions
  
          Input:
              recipient_id: recipient id to send to
              action: action type (mark_seen, typing_on, typing_off)
          Output:
              Response from API as <dict>