"Add-ons" summarizes modules, templates and languages. Here you can install or remove add-ons.
By clicking on the "Advanced" button at the top right, an administrative tool to synchronize the information about add-ons which is stored in the database with the files on the server becomes visible.
Attention! Security Advice! Please make sure that only trustworthy users have access to this area. Bad minded users could abuse the upload of modules, templates or languages to load malicious scripts onto the server!