add_action('rest_api_init', function () {
    register_rest_route('custom/v1', '/version', array(
        'methods' => 'GET',
        'callback' => function () {
            if (!current_user_can('manage_options')) {
                return new WP_REST_Response(['error' => 'Unauthorized'], 403);
            }

            return new WP_REST_Response([
                'data' => get_bloginfo('version'),
            ]);
        },
        'permission_callback' => function () {
            return current_user_can('manage_options'); // Only admins can use it
        }
    ));
});
<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="https://geothermalpark.is/sitemaps_xsl.xsl"?>
<sitemapindex 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/siteindex.xsd" xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc>https://geothermalpark.is/post-sitemap1.xml</loc>
<lastmod>2026-03-23T14:21:40+00:00</lastmod>
</sitemap>
<sitemap>
<loc>https://geothermalpark.is/page-sitemap1.xml</loc>
<lastmod>2026-01-23T13:37:26+00:00</lastmod>
</sitemap>
</sitemapindex>