How to install plugins on a rental Nitrado server

hello am trying to install plugins for my new server. Unfortunately i only see instructions that are clear for single player. On a rental server am at sea as to what to do. I read red51's instructions on how to install a plugin folder and a sub folder this is where am stuck..Attacged is a screenshot of what i attempted to do without success

i did change the folder to read as plugins not Plugins.

Oh thank you soo much i will look at it again Yahwho