Enter the key in the game; it will fail but generate a file named activation.scb Documents/Euro Truck Simulator 2 Transfer this file to an internet-connected device. Upload it to the official activation page
When prompted at the start screen, enter your unique product key. Online Verification: product key for euro truck simulator 2 1.15.1
Depending on your installation type, there are two primary ways to activate your product key: Launch the Steam client. Enter the key in the game; it will
If you are running the older standalone 1.15.1 version without the Steam client, you must use the internal legacy activation process: Enter the key in the game