[HHA Driver] Madtrucker24

this has not fixed it where should i be installing the application to cause at the moment it is set to C:\Program Files\Euro Truck Simulator 2\Euro Truck Simulator 2 Multiplayer

Hello to anyone that can help every time i install ets2 mp and try to launch it, Once installed on my computer i go to open the application and it just keeps coming up with"The program cant start because steam_api.dll is missing from your computer. try reinstalling the program to fix this problem'but every time i try it keeps doing the same thing and i cannot work. so if you could help it would greatly appreciated