How to solve the problem with Socket.io and Https?

Question

Apache HTTP Server

I put the script of the roulette of things. There is a bunch of apache + nodejs + socket.io. If you go to the site by IP address, then the site connects to the bot via a socket, everything is fine in the console. If you go to the site by domain, then it swears with two errors:

GET https://site.ru:2053/socket.io/?EIO=3&transport=polling&t=1564049380135-11 521

Access to XMLHttpRequest at 'https://site.ru:2053/socket.io/?EIO=3&transport=polling&t=1564049380135-11' from origin 'https://site.ru' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

I tried to configure CORS by adding to .htaccess

<IfModule mod_headers.c>
Header set Access-Control-Allow-Origin "*"
</IfModule>

but didn't help.

On the site in the scripts, the connection is also used, I
var socket = io.connect(':2053');also tried to specify var socket = io.connect(https://site.ru':2053');it, nothing helped.

App.js to start the bot is used with the following config:

var auth = require('http-auth'),
    scribe = require('scribe-js')(),
    console = process.console,
    config = require('./config.js'),
    app = require('express')(),
    server = require('https').Server(app),
    io = require('socket.io')(https),
    redis = require('redis'),
    requestify = require('requestify'),
  
  fs = require('fs'),
    privateKey = fs.readFileSync('/var/www/bot/keys/privkey.pem'),
    certificate = fs.readFileSync('/var/www/bot/keys/cert.pem'),
    credentials = {key: privateKey, cert: certificate},
    https = require('https').Server(credentials,app);

https.listen(config.serverPort);

I'm using cloudflare, so port 2053 is the one they have open.

What could be the problem?