The first thing you will need to do is be sure that the icon you have chosen follows these requirements.
Named as server-icon.png
In a .png file format
64×64 pixel size
You will firstly want to head to your control panel. From there, you will want to locate the left side bar menu, then select Files > FTP File Access.
Once in the FTP File Access, you will want to login.
You will want to put the server-icon.png in the main / home directory of the FTP server.
To upload the icon, you will want to select the upload button. Which is located to the left side bar menu.
Once at the upload page, you will want to choose the server icon file from your computer.
Now that you have it select, you will want to select the submit button.
Now that your server icon is uploaded, you can reboot your server for it to take effect.
Updated on: 02 / 05 / 2020