apfs-disable-coupons-for-products-on-subscription.php

<?php
/**
 * Plugin Name: All Products for WooCommerce Subscriptions - Disable Coupons for Products on Subscription
 * Plugin URI: https://woocommerce.com/products/all-products-for-woocommerce-subscriptions/
 * Description: Use this snippet to prevent coupons from applying to cart items on Subscription.
 * Version: 1.0
 * Author: WooCommerce
 * Author URI: https://woocommerce.com/
 * Developer: Jason Kytros
 *
 *
 * Copyright: © 2021 Automattic.
 * License: GNU General Public License v3.0
 * License URI: http://www.gnu.org/licenses/gpl-3.0.html
 */
 
add_filter( 'woocommerce_coupon_is_valid_for_product', 'apfs_disable_for_products_on_subscription', 10, 4 );

function apfs_disable_for_products_on_subscription( $is_valid,  $product,  $instance,  $values ) {
	if ( ! empty( $values[ 'wcsatt_data'][ 'active_subscription_scheme' ] ) ) {
		$is_valid = false;
	}
	return $is_valid;
}