input: 
  def create_flask_app() -> Flask:
      """ Create a Python 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 = create_flask_app()
      >>> app.run(port=5000, debug=True)
      Starting app on port 5000
      """
  
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)
          result = makeWebhookResult(req)
          return jsonify(result)
  
      def makeWebhookResult(req):
          speech = "Hello, this is a response from the webhook."
          return {
              "speech": speech
          }
  
      return app
  