Version 1.45 was a "bridge" update that significantly closed the quality gap between the aging base game map and newer DLC expansions. It remains a popular version for those using specific legacy mods or older ProMods versions that haven't been updated to the current game engine. If you'd like more details, I can: Find the for this version.
The easiest and most secure way to access ETS2 is through the Steam store Steam Users: Download Euro Truck Simulator 2 Version 1.45