peer.on("open") never gets called

Question

I am creating a video call application using webrtc, peerjs, and socket.io. Everything works well locally until I push and deploy to vercel.

The peer.on("open") doesn't even get triggered, tried with my server and the peer cloud server too

This is my connection code

peer = new Peer({
            host: 'test-api.iludate-agentur.com',
            port: 443,
            path: '/peerjs',
            secure: true,
            config: {
                iceServers
            }
        });

I also tried using just

peer = new Peer()

They both work locally but not when deployed

This is my peer.on("open") code

peer.on('open', async (id) => {
            console.log('Here');
            // Join room
            socket.emit('join-room', bookingId, id);

            // Answer call
            peer.on('call', (call) => {
                call.answer(localStream);

                call.on('stream', (stream) => {
                    remoteStream = stream;
                    remotePlayer.srcObject = stream;
                    remotePlayer.play();
                });
            });
        });

This doesn't even get fired at all

Note: All of this work until I deploy to vercel

I was previously using the peer cloud server and thought it wouldn't work on https. So i deployed my own peer server, the elastic beanstalk load balancer has ssl configured already so i didn't bother doing the ssl code on my end anymore

This is what the server code looks like on my end

  // Set up peer server
  const peerServer = ExpressPeerServer(app.getHttpServer(), {
    path: '/',
    allow_discovery: true,
  });

  app.use('/peerjs', peerServer);