当使用优惠券完成新订单时，发送电子邮件

/**
 * WooCommerce Extra Feature
 * --------------------------
 *
 * Send an email each time an order with coupon(s) is completed
 * The email contains coupon(s) used during checkout process
 *
 */ 
function woo_email_order_coupons( $order_id ) {
        $order = new WC_Order( $order_id );
 
        if( $order->get_used_coupons() ) {
 
          $to = 'youremail@yourcompany.com';
          $subject = 'New Order Completed';
          $headers = 'From: My Name ' . "rn";
 
          $message = 'A new order has been completed.n';
          $message .= 'Order ID: '.$order_id.'n';
          $message .= 'Coupons used:n';
 
          foreach( $order->get_used_coupons() as $coupon) {
            $message .= $coupon.'n';
          }
          @wp_mail( $to, $subject, $message, $headers );
        }
}
add_action( 'woocommerce_thankyou', 'woo_email_order_coupons' );

在哪里添加此代码？

将PHP代码放在主题或子主题functions.php文件的底部。