To avoid third-party coupon conflicts with URL coupons

Prevent URL coupons from conflicting with third-party coupons.

add_action('wp_loaded', function (){
    if (isset($_GET['wdr_coupon']) && !empty($_GET['wdr_coupon']) ) {
        add_filter('woocommerce_coupon_is_valid', '__return_true');
    }
}, 1);