input: def create_flask_app() -> None:
      """Create a Python Flask app that listens for POST requests on the '/webhook' route. 
      The app should 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.
      
      >>> (Request to Flask app with action "productos.sura" and parameters {"tipo_cliente": "empresas"})
      >>> '{"speech": "Buscando productos para empresas", "displayText": "Buscando productos para empresas", "source": "apiai-onlinestore-shipping"}'
      """
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')
              speech = f"Buscando productos para {tipo_cliente}"
              return {
                  "speech": speech,
                  "displayText": speech,
                  "source": "apiai-onlinestore-shipping"
              }
          return {
              "speech": "Acción no reconocida",
              "displayText": "Acción no reconocida",
              "source": "apiai-onlinestore-shipping"
          }
  
      if __name__ == '__main__':
          app.run(port=5000, debug=True)
  