remove next ordercoupon in order notification email

remove_coupon_in_notification.php

add_filter('rnoc_before_displaying_next_order_coupon', "rnoc_before_displaying_next_order_coupon", 10, 2);
/**
* @param $message
* @param $order \WC_Order
* @return string
*/
function rnoc_before_displaying_next_order_coupon($message, $order)
{
	if (method_exists($order, 'get_billing_email')) {
		$order_email = $order->get_billing_email();
		$args = array(
			'meta_key' => 'email',
			'meta_value' => $order_email,
			'post_type' => 'rnoc_order_coupon',
			'posts_per_page' => -1
		);
		$posts = get_posts($args);
		if (count($posts) == 1) {
			return $message;
		} else {
			$message = "";
		}
	}
	return $message;
}