All plugin versions you can update right from your WordPress admin area. All you need is add your license in the plugin settings tab.
If you bought Catchers Helpdesk from CodeCanyon (Envato market) – you need to fill only Envato Personal Token field.
See step by step guide how to get it.
If you bought Catchers Helpdesk from the official site – you need to fill only Plugin license field.
You can get this license from e-mail with your purchase.
After adding your license, please save changes. Since that moment you’ll be able to update your version from admin area your WordPress site.