how can have controll calls in peerjs

Question

i'm going to build a webrtc application and i want to controll peerjs calls from peer server to check if a user have access to call to another peer, the server will allow the user access to the call and otherwise the server will not allow access ... how i can do this system ??? it seems peerjs server have just connection and disconnect event, how can i controll peerjs calls ?

const http = require('http');
const express = require('express');
const { ExpressPeerServer } = require('peer');

const app = express();

const server = http.createServer(app);
const peerServer = ExpressPeerServer(server, {
    debug: true,
    path: '/'
});

app.use('/', peerServer);

peerServer.on('connection', (client) => {
    console.log(client);
});

server.listen(9000);