You have to place any of the textures ( Number 1 or Number 2 )  into folder

pCars \ Vehicles \ Textures \ CustomLiveries

You could have this folder in your steam library SteamLibrary \ steamapps \ common \ 

Once in game go to My Garage -> Edit Car -> Open Wheel -> Lotus Classic -> Lotus Type 98T Renault Turbo

Browse until you find the custom library