It's important to clarify that sharing or requesting specific product keys for Euro Truck Simulator 2 (or any software) would violate copyright laws and the terms of service of most platforms. Product keys are unique, legally protected identifiers meant to verify a legitimate purchase.

Activating your key on Steam allows the game to automatically update and seamlessly manage any purchased DLC. Launch the Steam Client on your desktop.

SCS Software has, over the years, blacklisted known pirated keys, often causing the game to revert to demo mode mid-delivery. Conclusion

Verify your purchase history on the site where you bought the key (e.g., Amazon, Humble Bundle SCS Software 2. Physical Retail Box

Here is the official, safe method: