Custom Text on Product Page based on Shipping Class [closed]

To display something above the product page, hook into woocommerce_before_single_product, and to get the shipping class use the get_shipping_class() method on the product, which can be retrieved with wc_get_product():

function wpse_295878_shipping_banner() {
    $product = wc_get_product();

    $shipping_class = $product->get_shipping_class();

    switch ( $shipping_class ) {
        case 'free-shipping':
            echo '<div class="woocommerce-info">Free shipping on this item</div>';
            break;
        case 'flat-rate':
            echo '<div class="woocommerce-info">Flat rate shpping $10</div>';
            break;
    }
}
add_action( 'woocommerce_before_single_product', 'wpse_295878_shipping_banner', 20 );