public function postToWishlist() {
        $requiredFields = ['postId', 'sku'];
        foreach ($requiredFields as $field) {
            if (empty($_POST[$field])) {
                $emessage = $this->master->estore->getErrorCodeMap()[Store::UNKNOWN_ERROR]->message;
                return $this->master->estore->getErrorResponse(Store::REQUIRED_FIELDS_MISSING, [$field], [$emessage]);
            }
        }

        $post_id = (int)$_POST['postId'];
        $sku = (string)$_POST['sku'];
        $item_option = isset($_POST['itemOption']) ? $_POST['itemOption'] : [];
        $advance = isset($_POST['advance']) ? $_POST['advance'] : '';

        $added = $this->addToWishlist($post_id, $sku, $item_option, $advance);
        if ($added !== true) {
            return $added;
        }

        if ($_SERVER['HTTP_REFERER']) {
            $_SESSION['usces_previous_url'] = esc_url($_SERVER['HTTP_REFERER']);
        } else {
            $_SESSION['usces_previous_url'] = str_replace('https://', 'http://', get_home_url()) . '/';
        }

        return 'success';
    }