Why is the event not processed in Bitrix24?

Question

Bitrix24

Good afternoon!

I put an event in init.php (I tried to change an element) but they do not work, tell me why? What I found on the forums did not help.
Here is the event code that I indicate, I try to print it here (I do everything as in the lessons from Bitrix):

<?
AddEventHandler("main", "OnBeforeEventAdd", array("MyEventAdd", "OnBeforeEventAddHandler"));
class MyEventAdd
{
    function OnBeforeEventAddHandler(&$event, &$lid, &$arFields)
    {
        var_dump($event);
    var_dump($lid);
    var_dump($arFields);
    }
}
?>