Steam typically updates the game automatically. If it hasn't, you can force the update by right-clicking Euro Truck Simulator 2 in your Library, selecting Properties , and navigating to the Updates tab to ensure "Always keep this game updated" is selected.
The update expanded the "Ownable" trailer series, allowing players to purchase and customize: This is how to upgrade or downgrade your | OBiFLY Euro Truck Simulator 2 1.47 Download
You can download the official updater from the Euro Truck Simulator 2 Updater page. Simply move the updater file to your game installation folder and run it. Steam typically updates the game automatically