boyle bir hata alıyorum acil yardım gerekiyor

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "optikler";
 
// bağlantı oluşturuyoruz
$conn = new mysqli($servername, $username, $password, $dbname);
 
$sql = "SELECT * FROM oc_product_description";
$result = $conn->query($sql);
?>
 
<?php header('Content-type: application/xml; ',true);  ?>


 
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
 
<?php while($row = $result->fetch_assoc()) { ?>
 
    <url>
            <name><?php echo ''.$row["name"]; ?></name>

        <link><?php echo 'https://www.optikler.com/index.php?route=product/product&amp;product_id='.$row["product_id"]; ?></link>
            </url>
 
<?php } ?>
 
 
 
</urlset>
sorun karakterde ama nasıl düzeltebilirim