While exaroton does not support FTP, it is possible to upload all sorts of files, including custom mods and plugins, to your server.
In directories that allow file uploads, you will see an upload button in the file manager. Clicking it will open a dialog that lets you select one or more files to upload to your server.
It is also possible to drag and drop files and folders directly into the file manager.
Most files and folders can also be downloaded from your server by clicking the download button.