Socket io as a service with Express REST API

Question

I have a REST api using express server and I want to receive notifications from certain routes using Socket.io as a service.

Can I emit from withing an express route on a already running express server and have a client listening to my api on it's root to log notifications?

What I'm trying to do:

in my route controller

exports.authenticate = (req, res) => {
... on success:
    socket = io()
socket.emit('logged in', "new user logged in")
}

my socket io client:

let socket = io('localhost:3000', {cors: { origin: '*' }})
socket.on('logged in', () => {
console.log("login notification")
})

I'm running my api alone, and then I'm running my client script using node client. but I'm not receiving anything