I need help with websocket implemetation

[GustavoSwDaniel]

I'm trying to implement a websocket but it was always being long polled.
I installed the eventlet but I have an error

Thank you in advance
__ init __.py

from flask import Flask
from flask_socketio import SocketIO
from flask_cors import CORS

socketio = SocketIO(logger=True, engineio_logger=True)

def create_app():
    app = Flask(__name__)
    app.debug = True
    app.config['SECRET_KEY'] = 'gjr39dkjn344_!67#'

    CORS(app)

    from app.user import bp as user_bp
    app.register_blueprint(user_bp)

    socketio.init_app(app, cors_allowed_origins="*", async_mode='eventlet')

    return app

app.py

from app import create_app, socketio

app = create_app()

if __name__== '__main__':
    socketio.run(app)

js client

 <script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.3.0/socket.io.js"></script>
    <script>
        window.onload = function(){
            const socket = io();
            
            function AddToChat(msg) {
                const span = document.createElement("span");
                const chat = document.querySelector(".chat");
                span.innerHTML = `<strong>${msg.name}:</strong> ${msg.message}`;
                chat.append(span);
            }

            socket.on('connect', () => {
                socket.emit('Usuário conectado ao socket!')
            });

            document.querySelector("form").addEventListener("submit", function(event){
                event.preventDefault();

                socket.emit('sendMessage', {name: event.target[0].value, message: event.target[1].value})
                event.target[0].value = "";
                event.target[1].value = "";
            })

            socket.on('getMessage', (msg) => {
                AddToChat(msg)
        
            })
            
            socket.on('message', (msgs) => {
                for(msg of msgs){
                    console.log(msg)
                    AddToChat(msg)
                }
            })
        }

error:

[miguelgrinberg]

The error explains the problem. You must be running the Flask development web server, not the eventlet server.

Are you using flask run to start the server, by any chance? You have to use socketio.run(app) so that the correct web server is used.

[GustavoSwDaniel]

Yep, I'm using flask run, but when I use socketio.run(app) I get that the command is invalid

[GustavoSwDaniel]

I think I understand.
I used python3 app.py so it worked kk

[GustavoSwDaniel]

Is that what you meant?

That's right?

[miguelgrinberg]

Yes. Does everything work?