If you did what was instructed on the Gamemodepage and Nyx was unable to detect your gamemode; then you will need to manually tell the script what gamemode you are running.
Open the gamemode loader file located in lua\modules\nyx\cfg\sh_1_gamemodes.lua
You will see a list of gamemodes, with information for each one. Determine what gamemode best explains what you are running. If it is based on darkrp; then you can add your new gamemode under the darkrp listings: