Send cancelled and failed order email to customer in Woocommerce 3
问题 I need to send cancelled and failed order email to customers in Woocommerce 3.4+ . I'm constantly getting Fatal error: Uncaught Error: Call to a member function get_billing_email() on null in I've tried few function (like below) from stackoverflow with same result: function wc_cancelled_order_add_customer_email( $recipient, $order ) { return $recipient .= "," . $order->get_billing_email(); } add_filter( 'woocommerce_email_recipient_cancelled_order', 'wc_cancelled_order_add_customer_email', 10