Socketio background task not running

I am creating a multiplayer online game, and am using socket io for the game server. Below is my server code

import socketioimport timefrom aiohttp import websio = socketio.AsyncServer(async_mode='aiohttp', cors_allowed_origins='*', async_handlers=True)app = web.Application()sio.attach(app)@sio.on('connect')def connect(sid, environ):    print("connected: ", sid)@sio.on('disconnect')def disconnect(sid):    print('disconnect ', sid)async def background_thread():    while True:        print("here")        sio.emit('message', {'data': 'Server generated event'})        time.sleep(5)if __name__ == '__main__':    print ("Starting server")    sio.start_background_task(background_thread)    web.run_app(app, port=3000)

But the problem is the above code starts up the server but the background task is not running, where am I going wrong?