function wp_maintenance_mode() {
if (!current_user_can('edit_themes') || !is_user_logged_in()) {
wp_die('<h1>Under Maintenance</h1><br />Website under planned maintenance. Please check back later.');
}
}
add_action('get_header', 'wp_maintenance_mode');<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://oxygenconcentratorservices.com/wp-sitemap.xsl" ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><url><loc>https://oxygenconcentratorservices.com/</loc></url></urlset>