Template apps can only be updated from the Mabui studio. Unlike normal private and public apps, templates can be re-published.
1. Open your published template app from the Mabui studio screen.
2. Make your updates.
3. Go to the publishing screen - you will see the message "This template app has been published..." Click on "Start pre-publishing checks".
4. If everything is OK click "Go to publishing" then "Publish my app".
5. Your updated template will now be available to the public.