Custom #_WAITLIST_BOOKING_URL Placeholder

add_filter('em_booking_output_placeholder','my_em_placeholders_custom_bookingid',100,3);
function my_em_placeholders_custom_bookingid($replace, $EM_Booking, $result){
	switch( $result ){
		case '#_WAITLIST_BOOKING_URL':
			$url =  esc_url($EM_Booking->get_event()->get_permalink());
			$query_args = array('pno' => null, 'uuid' => $EM_Booking->booking_uuid, 'waitlist_booking' => 1);
			if( $EM_Booking->person_id == 0 ){
				$query_args['email'] = urlencode($EM_Booking->booking_meta['registration']['user_email']);
			}
			$replace = add_query_arg( $query_args, $url );
			break;
	}
	return $replace;
}