input:  
  def create_flask_app() -> Flask:
      """
      Create a Flask app that listens for POST requests on the '/webhook' route. Extract 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:
      >>> app = create_flask_app()
      >>> client = app.test_client()
      >>> response = client.post('/webhook', json={"result": {"action": "productos.sura", "parameters": {"tipo_cliente": "nuevo"}}})
      >>> response.get_json()['speech']
      'Buscando productos para nuevo'
      """
  
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', 'desconocido')
              speech = f'Buscando productos para {tipo_cliente}'
          else:
              speech = 'Acción no reconocida'
          return {'speech': speech}
  
      if __name__ == '__main__':
          app.run(port=5000, debug=True)
  