title: WebSocket transport not available. Install simple-websocket for improved performance
body: <h3>Here is my full app code</h3>
  <pre><code>from flask import Flask, render_template, request, session, redirect, url_for
  from flask_socketio import SocketIO, join_room, send
  
  
  app = Flask(__name__)
  app.config['SECRET_KEY'] = 'secretjsidfjsidfjsdifjsdifj!'
  socketio = SocketIO(app)
  
  
  @app.route('/')
  def index():
      return render_template('index.html')
  
  @socketio.on('message')
  def handle_message(msg):
      print('get message:'+ msg)
      send(msg, broadcast=True)
  
  
  if __name__ == &quot;__main__&quot;:
      socketio.run(app)
  </code></pre>
  <p>When I run the socketio server, it shows</p>
  <pre><code>skysea@qiuyuxuandeAir flask-test % python3 app.py
  WebSocket transport not available. Install simple-websocket for improved performance.
   * Serving Flask app &quot;app&quot; (lazy loading)
   * Environment: production
     WARNING: This is a development server. Do not use it in a production deployment.
     Use a production WSGI server instead.
   * Debug mode: off
   * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
  http://localhost:5000 is not an accepted origin. (further occurrences of this error will be logged with level INFO)
  127.0.0.1 - - [28/May/2021 12:42:45] &quot;GET /socket.io/?EIO=4&amp;transport=polling&amp;t=NcnI2J7 HTTP/1.1&quot; 400 -
  </code></pre>
  <p>But I have installed simple-websocket</p>
  <p>Here is my Flask-socketIO information</p>
  <pre><code>skysea@qiuyuxuandeAir flask-test % pip3 show flask_socketio 
  Name: Flask-SocketIO
  Version: 5.0.3
  Summary: Socket.IO integration for Flask applications
  Home-page: http://github.com/miguelgrinberg/Flask-SocketIO/
  Author: Miguel Grinberg
  Author-email: miguelgrinberg50@gmail.com
  License: MIT
  Location: /opt/homebrew/lib/python3.9/site-packages
  Requires: python-socketio, Flask
  Required-by: 
  </code></pre>
  <p>Here is my simple-websocket information</p>
  <pre><code>skysea@qiuyuxuandeAir flask-test % pip3 show simple-websocket
  Name: simple-websocket
  Version: 0.2.0
  Summary: Simple WebSocket server and client for Python
  Home-page: https://github.com/miguelgrinberg/simple-websocket
  Author: Miguel Grinberg
  Author-email: miguel.grinberg@gmail.com
  License: UNKNOWN
  Location: /opt/homebrew/lib/python3.9/site-packages
  Requires: wsproto
  Required-by: 
  </code></pre>
  <p>I use Mac M1, how can I fix this problem?</p>