Variable product price (range) discount or strikeout is not shown

Fix the issue where discount or strikeout prices for variable products are not displayed.

add_filter('woocommerce_get_price_html', function($html, $product){
    if(is_object($product) && method_exists($product, 'get_type') && $product->get_type() == 'variable') {
        if (class_exists('\Wdr\App\Router') && method_exists(\Wdr\App\Router::$manage_discount, 'getVariablePriceHtml')) {
            return \Wdr\App\Router::$manage_discount->getVariablePriceHtml($html, $product);
        }
    }
    return $html;
}, 9999, 2);