The process is as follows:
Step 1: Navigate to the Unturned Steam Workshop.
Step 2: Subscribe to the mods that you would like added to your server.
Step 3: Locate the mods that you have subscribed to on your pc. These can typically be found in "SteamLibrary\SteamApps\workshop\content\304930".
NOTE* 304930 is Unturned's ID. You'll see numbered folders in that folder. These are the workshop mods.
Step 4: Upload your subscribed mods via FTP to this location on your server >Pingperfect>Workshop>content.
Step 1: Stop your server
Step 2: Install Rocket Mod from the Mod Manager on your control panel.
Step 3: Download your plugins from the Rocket Mod website. Be sure to unzip the folder.
Step 4: Upload the unzipped files to the folder Servers\Pingperfect\Rocket\Plugins\ using the File Manager or FTP. Help with setting up FTP can be found here.
Step 5: Setup the plugin following instructions are given on the plugins page. Most plugins will have permissions that need to be set up before they can be used.
Step 6: Start your server