Slack Python Listening Events

I'm trying to learn how to crate Slack Apps using the Slack Bolt Framewok, so I'm studying this tutorial (https://api.slack.com/start/building/bolt-python). I followed all the steps but my bot is not listening to the events.

The python class:

import os
from slack_bolt import App

app = App(
    token = 'xoxb-xxxxxxxx-2463004875172-0pnMlWzr30pFg2vFGtt52wzx',
    signing_secret = 'xxxxxxx3eba2b1fc11bf6076'
)

# Start your app
if __name__ == "__main__":
    app.start(port=int(os.environ.get("PORT", 3000)))

@app.event("message")
def handle_message_events(body, logger):
    logger.info(body)

The response I get when I write a message to the bot: response

The response in the ngrok: ngrok response

The bot events subscriptions subscriptions

Does anyone know what I am forgetting to do?

Solution

As per the official documentation, functionality goes before you start the app.
https://github.com/slackapi/bolt-python#creating-an-app

app = App()

# Add functionality here

if __name__ == "__main__":
    app.start(3000)  # POST http://localhost:3000/slack/events

Can you move following code accordingly, and check?

 @app.event("message") 
 def handle_message_events(body, logger):
 logger.info(body)