Как установить в socket.io заголовки headers

Пытаюсь настроить более безопасное взаимодействие с socket.io на портале но пока без особых успехов. В документации нашел вариант установки заголовков,

  io.engine.on("initial_headers", (headers, request) => {
        headers["X-Frame-Options"] = 'SAMEORIGIN';
        headers["set-cookie"] = "mycookie=456";
    });

попробовал и что-то не так, внизу скрин: куки установились а вот X-Frame-Options нет. Весь файл -

#!/usr/bin/env node
const fs = require('fs');
const path = require('path');

const httpsOptions = {
    key: fs.readFileSync(path.resolve(__dirname,'../ssl/privkey.pem')),
    cert: fs.readFileSync(path.resolve(__dirname,'../ssl/cert.pem'))
};

/**
 * Module dependencies.
 */

let app = require('../app');

// let debug = require('debug')('nagib:server');
//   let http = require('http');
let https = require('https');

/**
 * Get port from environment and store in Express.
 */


// let port = normalizePort(process.env.PORT || '80');
let port = normalizePort( '443'); // 443
app.set('port', port);

/**
 * Create HTTP server.
 */

let server = https.createServer(httpsOptions, app);
 

// Redirect from http port 80 to https
let http = require('http');
http.createServer(function (req, res) {
    res.writeHead(301, { "Location": "https://" + req.headers['host'] + req.url });
    res.end();
}).listen(80);
/**
 * Listen on provided port, on all network interfaces.
 */


let io = require('../api/modules/io');

io.attach(server,{
    cookie: {
        name: "sock_",
            httpOnly: true,
            path: "/"
    }

});

require('../api/modules/session').setSession;

io.engine.on("initial_headers", (headers, request) => {
    headers["X-Frame-Options"] = 'SAMEORIGIN';
    headers["set-cookie"] = "mycookie=456";
});


server.on('error', onError);
server.on('listening', onListening);


/**
 * Normalize a port into a number, string, or false.
 */

function normalizePort(val) {
    let port = parseInt(val, 10);

    if (isNaN(port)) {
        // named pipe
        return val;
    }

    if (port >= 0) {
        // port number
        return port;
    }

    return false;
}

/**
 * Event listener for HTTP server "error" event.
 */

function onError(error) {
    if (error.syscall !== 'listen') {
        throw error;
    }

    let bind = typeof port === 'string'
        ? 'Pipe ' + port
        : 'Port ' + port;

    // handle specific listen errors with friendly messages
    switch (error.code) {
        case 'EACCES': 
            process.exit(1);
            break;
        case 'EADDRINUSE': 
            process.exit(1);
            break;
        default:
            throw error;
    }
}

/**
 * Event listener for HTTP server "listening" event.
 */

function onListening() {
    let addr = server.address();
    let bind = typeof addr === 'string'
        ? 'pipe ' + addr
        : 'port ' + addr.port; 
}