Logout button or link in the top menu

Hi, everybody!

I want to put a logout button or link in the top menu.

I’ve searched the wordpress.org site but I didn’t see clearly the way to do it.

When I tried to get a logout & redirect to homepage link putting <a href="<?php echo wp_logout_url( home_url() ); ?>" title="Logout">Logout</a> in the WP menu url field, and click Save Menu, the Menu rewrite ahref and become useless.

Then, I found this as example and I think that I have to put it in enfold-child theme functions

add_filter('allowed_redirect_hosts','allow_ms_parent_redirect');
function allow_ms_parent_redirect($allowed)
{
    $allowed[] = 'multisiteparent.com';
    return $allowed;
}

<a href="<?php echo wp_logout_url( 'http://multisiteparent.com' ); ?>" title="Logout">Logout</a>

How can I get it?

Thanks!

Best regards!