The administrative control panel is virtual.
By default, the address is: your_site/admin
It is worth noting that if you do not have access rights to the administrative panel (not authorized with access rights to the control panel), when requesting the address, you will see error 404 (page does not exist).
You can change the address only in the site configuration file (rk-config.php in the root of the site).
To do this, you need to add the following line of code to the file:
define('RK_ADMINPAGE_PATH', 'foldername');
