The system files include twi folders "Latest - Update"


1.3.5 has been released today, so yeah, you should update if you're not running any campaign at the moment.
In the archive you will also find a README that will explain what those two folders inside are and how to do the update. Basically you just need to use the folder called "update" and upload it's contents over your existing mailwizz contents on your server.

Make sure you login into backend before you start the update process.