Display total participant as order item quantity in email (If Consider each participant as separate booking is enabled)

function.php

function display_total_participant_in_email_order_item_quantity($quantity,$item =array()) {
	if(!empty($item) && !empty($item->get_product_id())  ) {
		$product_id=$item->get_product_id();
		$_persons_as_booking 		= get_post_meta( $product_id, "_phive_booking_persons_as_booking", 1 );
		if($_persons_as_booking=='yes')
		{
			$no_of_persons=$item->get_meta('Number of persons',true);
			if(!empty($no_of_persons))
			{
				return $no_of_persons;
			}
			else
			{
				return '-';
			}
		}
		else
			return '-';
	}
	return $quantity;
}
add_filter( 'woocommerce_email_order_item_quantity', 'display_total_participant_in_email_order_item_quantity',10,2 );