help setting up nitrado dedicated server with mods on SMM

hi sorry if im being thick can someone help me . complete noob to dedicated servers. i have paid for a nitrado server and connected my game to it but now i want to add mods but i cant seem to work out what to put where in the FTP dedicated server window on SMM. no matter what i do it doesn't work also i know om probably being stupid here but i don't know what path it is asking for please help