How to enable Developer Console in American Truck Simulator
While your game is not on. Locate the game's data folder
This tends to be in your documents folder.Open the American Truck Simulator Folder
Open Config.cfg
Search uset g_developer "0"
Change it to 1.
Search uset g_console
Change to 1
Save & Start game


You should now be able to press ` to open the console.