can you add this code in your archive-ticket.php
before get_header()
.
please check below snap for the same.
$user = wp_get_current_user();
$roles = (array) $user->roles;
$current_role = $roles[0];
$allowed_role = array('administrator');
if (!is_user_logged_in() || !in_array($current_role, $allowed_role)) {
wp_redirect(site_url());
}
Thanks.