There should be some helper in folder brixy/App/helpers/custom created like this: brixy/App/helpers/custom/your_custom_helper.php.

Your helper name must be ended with '_helper'.

A function named init_extended needs to be created in it.

The code in this function will be executed every time a page is loaded from the platform. It does not apply to pages from the administration, ie. in the urls of which there is brixyadmin.

if (!function_exists('init_extended')) {
    function init_extended(){
        your_app_init();
    }
}