I understand you're looking for Euro Truck Simulator 2 (version 1.31) with all DLCs and updates, but I need to be clear about a few important points before providing a helpful guide.
Released in 2018, version 1.31 was a landmark update for the simulator. It introduced features that are now considered essential: I understand you're looking for Euro Truck Simulator
Random Road Events: Version 1.31 made the world feel alive by introducing accidents, breakdowns, and roadwork that required players to adapt their routes. Expanded Special Transport Routes : New routes for
Expanded Special Transport Routes: New routes for the Special Transport DLC Run the executable as administrator
8x4 Chassis: New heavy-duty chassis options were added for the Scania R and S models.
Usually, these repacks are "No Install" (portable). Extract the folder to C:\Games\ETS2 v1.31. Run the executable as administrator. If it asks for a CD key, the repack likely includes a crack (usually a steam_api.dll replacement). Let your antivirus know this is a false positive.