input: def handle_webhook_requests(app: Flask) -> None:
      """ Create a Flask app that listens for POST requests on the '/webhook' route. When a request is received, extract the necessary parameters from the request and call the 'makeWebhookResult' function to generate a response. The response should be a JSON object containing a 'speech' field with the text to be spoken by the voice assistant. The app should be started on port 5000 and run in debug mode.
      >>> app = Flask(__name__)
      >>> @app.route('/webhook', methods=['POST'])
      ... def webhook():
      ...     req = request.get_json(silent=True, force=True)
      ...     res = makeWebhookResult(req)
      ...     res = json.dumps(res, indent=4)
      ...     r = make_response(res)
      ...     r.headers['Content-Type'] = 'application/json'
      ...     return r
      ...
      >>> handle_webhook_requests(app)
      """
output:     app.run(port=5000, debug=True)