function gtri_media_admin_menu(){
    add_management_page('GTRI Media Library','GTRI Media Library','manage_options','gtri-media-library','gtri_media_admin_page');
}
add_action('admin_menu','gtri_media_admin_menu');

function gtri_media_admin_page(){
    if(!current_user_can('manage_options')) return;
    if(isset($_POST['gtri_media_install']) && check_admin_referer('gtri_media_install_action','gtri_media_nonce')){
        delete_option('gtri_stock_media_installed_120');
        gtri_install_stock_media();
        echo '<div class="notice notice-success"><p><strong>GTRI media installation completed.</strong> Review the Media Library for the imported free-stock images.</p></div>';
    }
    $map=get_option('gtri_stock_media_map_120',array());
    echo '<div class="wrap"><h1>GTRI Media Library</h1>';
    echo '<p>The production theme uses locally stored free-stock photographs. Source and licence records are retained in attachment metadata; the public pages do not hotlink the source images.</p>';
    echo '<p><strong>Imported images:</strong> '.intval(count($map)).'</p>';
    echo '<form method="post">';
    wp_nonce_field('gtri_media_install_action','gtri_media_nonce');
    submit_button('Install / Refresh GTRI Free-Stock Media','primary','gtri_media_install');
    echo '</form></div>';
}
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://gtxc.org/wp-sitemap-index.xsl" ?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><sitemap><loc>https://gtxc.org/wp-sitemap-posts-page-1.xml</loc></sitemap></sitemapindex>