SCS Software, the developer, actually offers the base game (often including v 134025s as a beta branch) for as low as $5 during Steam sales. There is also a free demo. If budget is zero, look for or Epic Game Store freebies (though ETS2 is rarely there).
The safest and most reliable way to play the game is through official platforms. Official Ways to Play : You can download a free demo of Euro Truck Simulator 2 on Steam
Players might prefer the game mechanics or map layout of that particular release. Where to Find the Free Download Safely