Calculate Sales by Coupon Code - The Complete Web development company

function bbloomer_get_sales_by_coupon($coupon_id) {
    $args = [
        'post_type' => 'shop_order',
        'posts_per_page' => '-1',
        'post_status' => ['wc-processing', 'wc-completed', 'wc-on-hold']
    ];
    $my_query = new WP_Query($args);
    $orders = $my_query->posts;
    $total = 0;
    foreach ($orders as $key => $value) {
   
    $order_id = $value->ID;
    $order = wc_get_order($order_id);
    $items = $order->get_items('coupon'); 
    foreach ( $items as $item ) {
    if( $item['code'] == $coupon_id ) {
                $total += $order->get_total();
        }
    }
    
    }
    return 'Total sales for coupon "' . $coupon_id . '": ' . wc_price($total);
}
// -------------------------
// 2. Add new tab to WooCommerce "Reports", and print the coupon total sales
add_filter( 'woocommerce_admin_reports', 'bbloomer_add_report_tab' );
function bbloomer_add_report_tab( $reports ) {
$reports['coupons'] = array(
                'title'  => __( 'Coupons', 'woocommerce' ),
                'reports' => array(
                    "sales_by_code" => array(
                        'title'       => __( 'Sales by code', 'woocommerce' ),
                        'description' => bbloomer_get_sales_by_coupon('barmada'), //change coupon code here
                        'hide_title'  => false,
                        'callback'    => '',
                    ),
                ),
            );
return $reports;
}
Where to add this code?
