Add custom badge to WooCommerce featured product

/**
 * Add custom badge to WooCommerce featured product.
 */
function wpsimpel_add_featured_product_badge() {

    global $product;

    if ( $product->is_featured() ) {
        echo '<span class="product-badge custom-badge">' . esc_html_e( 'Featured product', 'your-text-domain' ) . '</span>';
    }
}
add_action( 'woocommerce_before_shop_loop_item_title', 'wpsimpel_add_featured_product_badge' );
add_action( 'woocommerce_before_single_product_summary', 'wpsimpel_add_featured_product_badge' );