How would I pass a jwt from my redux store into my middleware that then sends a socket.io connect request to my backend?

In my React App, I initialize my websocket (using socketIO) via middleware, and then want to validate the socket connection with a JWT I retrieve from Auth0.

My backend middleware keeps getting null when I read the handshake. This leads me to believe that I haven’t yet recieved my token, so I’ve tried setting up a promise, with different configurations, but to no avail.

I would like to useSelector() but it’s not really a functional component, and I don’t know if I could use this with middleware.

Do I use a cb() in the io.( URL, { auth:{token: (cb) { token: 'abc' } } } ); ?

Code below:

middleware.tsx

const notificationMiddleware: Middleware = store => {
  let socket: Socket;
  const state = store.getState();
  let token:string|null = null;

  const tokenPromise = new Promise((resolve,reject)=>{
    token = state.auth.token;
    if(token !== null){
      resolve(token)
    }
  });

  tokenPromise.then((result)=>{
    console.log('Finished: ', result);
  })

  return next => action => {
    const isConnectionEsablished = socket && store.getState().notification.isConnected;

    if(notificationActions.startConnecting.match(action) && !isConnectionEsablished && token !== null){
      socket = io(process.env.REACT_APP_SERVER_URL, {withCredentials: true, auth: {token: token } });
      store.dispatch(notificationActions.connectionEstablished());
      console.warn('WebSockets connect');

      socket.on('connect', () => {  

      });

      socket.on('message', (res) => {
        console.info('Notification recieved, storing.', res)
        store.dispatch(notificationActions.receiveMessage(res));
      });

      socket.on('job', (res) => {
        console.info('job recieved, ', res);
        store.dispatch(socketJobPayload(res));
      });

      socket.on('indv', (res) => {
        console.info('indv event recieved, ', res);
        //send individual object
        store.dispatch(socketIndividualPayload(res.data));
        store.dispatch(socketJobMetrics(res.data));
        store.dispatch(socketEmployerMetrics(res.data.ieMetrics));
        //send metrics to job
      });

      socket.on("connect_error", (err) => {
        console.log(err.message); // prints the message associated with the error
      });
    }

    next(action);
  }
}

export default notificationMiddleware;

backend, if it matters

io.use( async(socket:any, next:any) => {
  try{
    const token = socket.handshake.auth.token;
    console.log(token);
    if(token === 'token-pass'){
      console.log('socket passed!')
      next();
    }else{
      next(new Error("thou shall not pass!"));
    }
  }catch(e){
    console.log(e);
  }
});