Slack event API response using python flask

I am working with slack event API. I am getting events on the subscribed events. But how to send respond using python requests. slack sends the same event back again after few seconds what json I need to send back to slack as a response to stop getting the same response? If you know the code, thank you so much in advance :)

@flask.route("/slack_webhook")
def slack_webhook():
    print("Slack Webhook.....!!!")

    data = json.loads(request.data.decode("utf-8"))
    if 'challenge' in data:
    return(data['challenge'])

    if data['type'] == 'event_callback':
        response = make_response("", 200)
        response.headers['X-Slack-No-Retry'] = 1
        print("returning response")
        return response

    else:
        slack_event_handler.delay(data)

Answer

directly return the status if successfully received required information.

return 'HTTP 200 OK'