While you want v1.39 for mods, the best mods (ProMods, RusMap, etc.) have long since updated to 1.49, 1.50, and 1.53. Trying to run modern mods on a frozen 1.39 portable version will result in constant crashes, missing textures, and broken roads.
The Last Portable Mile
Open the extracted folder and navigate to the bin directory. For 64-bit systems: bin\win_x64\eurotrucks2.exe For 32-bit systems: bin\win_x86\eurotrucks2.exe euro truck simulator 2 139 all dlc download portable
Beyond the Baltic Sea: Countries like Estonia, Latvia, and Lithuania. While you want v1