After installation, right-click Euro Truck Simulator 2 in your Steam Library → → Betas tab. In the dropdown menu labeled “Beta participation,” you will find a list of older versions. Look for an entry named “temporary_1_39 - 1.39.x for old mods” or similar wording. Select it. Steam will then downgrade your game to version 1.39 automatically.
After installation and activation, you're ready to launch the game: download euro truck simulator 2 139 install