How to download your savegame from your Unturned server
Navigate to your File Manager on the Fragify game panel.
Servers => Default. Once there, press the 3 dots on each marked Files and Folders on the screenshot and download them individually. Alternatively, you can mark them like in the screenshot, go to the lower right corner of the screen and click on archive, which will zip all of those files and then you can download the archive.
After all the files have been downloaded and unzipped, you need to go to your Unturned installation on your PC. The default location is
Program Files (x86)\Steam\steamapps\common\Unturned\Worlds\Singleplayer_0.
Once there, paste the files in this location, and overwrite everything when asked. If you have an archive, extract its' contents to the directory shown in the screenshot above.