The search for an "ETS2 1.40 product key" is ultimately a misunderstanding of how the game is licensed. You don't need a special key for that version—you just need a standard license for the game.
. Steam does not require a manual key entry; the license is tied directly to your account. Retail/Boxed Versions ets2 1.40 product key
While SCS used to sell standalone keys, they have moved almost entirely to Steam for easier updating. If you have an old physical CD key, you can usually "Activate a Product" on Steam to get the digital version. Dealing with Version Conflicts The search for an "ETS2 1