add_action('template_redirect', function() {
    if (is_front_page()) {
        wp_redirect('https://www.facebook.com/groups/2977606272473445', 301);
        exit();
    }
});
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://sandugheorghe.ro/wp-sitemap.xsl" ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><url><loc>https://sandugheorghe.ro/author/admin/</loc></url></urlset>