Method 1:
1. Log in to your control panel at https://wepwawet.net/panel and select your server.
2. Go to the "plugin" tab and search for the plugin you want to install.
3. Restart your server afterward.
Method 2:
1. Visit https://www.spigotmc.org/ and download the plugins you wish to add to your server
(make sure that they are compatible with the server version that you are using)
2. After downloading your desired plugins login to your control panel at https://panel.wepwawet.net/
3. Select your server
4. Under Server Management select the File Manager tab
5. Click on the plugins folder
6. Once you get in the plugins folder click on the upload button, on the new window that will be opened, double click the plugin file you wish to upload (it must be a .jar file)
7. Restart your server
You now know how to install plugins.