Event manager Hook em_booking_add

Hello Folks, i know that isn’t a really new topic, but i couldn’t get threw it. i’m pretty new to php ..
My goal is to add the custom field into the booking form.
I have already modify booking-field.php, classe/em-person.php and that ok.
My issue is on hooking em_booking_add and em_booking_save.
this my code:

function add_website (){
$_REQUEST['website'] = (!empty($_REQUEST['website'])) ? $_REQUEST['website']:'';
$EM_Booking->booking_meta['registration']['booking'] = array('website' => $_REQUEST['webiste']);
}

add_action('em_booking_add','add_website');

i put my code at the end of em-functions.php
if leave it like that the custom field (website) won’t be save,
so i though it was enough to add

add_action(’em_booking_save’,’add_website’);`
but it isn’t working.
What do i miss please?