How to find a redirect in Bitrix template files?

Question

1C-Bitrix

After transferring the site to the technical subdomain, when going to the site, it redirects to the mirror from www. There is no such redirect in htaccess, and the correct setting in this file does not work - the old redirect remains and the new one does not work. I tried all the options for redirect entries in htaccess offered on the Internet - all to no avail. There is an opinion that the redirect to the www version is somewhere in the header files, but I can't find it anywhere. Tell me what to do?

Answer 1

Interrupt the page execution process before calling the Bitrix template.
For example:

<?php
die('Hello!');
require($_SERVER["DOCUMENT_ROOT"]."/bitrix/header.php");

If the redirect is in Bitrix, then you will see "Hello!", if it is on the server side, then the redirect will still work.