input: def webhook_flask_app():
      """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.
      Example:
      >>> post_request_payload = {'result': {'action': 'productos.sura', 'parameters': {'tipo_cliente': 'cliente1'}}}
      >>> response = requests.post('http://localhost:5000/webhook', json=post_request_payload)
      >>> response.json()['speech']
      'Buscando productos para cliente1'
      """
output:     
      from flask import Flask, request, jsonify
  
      app = Flask(__name__)
  
      @app.route('/webhook', methods=['POST'])
      def webhook():
          req = request.get_json(silent=True, force=True)
          action = req.get('result', {}).get('action')
          parameters = req.get('result', {}).get('parameters', {})
          response = makeWebhookResult(action, parameters)
          return jsonify(response)
  
      def makeWebhookResult(action, parameters):
          if action == 'productos.sura':
              tipo_cliente = parameters.get('tipo_cliente', 'cliente')
              speech = f'Buscando productos para {tipo_cliente}'
          else:
              speech = 'Acción no reconocida'
          return {'speech': speech}
  
      if __name__ == '__main__':
          app.run(port=5000, debug=True)
  