Officially, no. SCS Software only distributes the game via Steam, the Epic Games Store, or physical media (which still requires Steam activation). Any website offering a direct download of the Euro Truck Simulator 2 1.38 setup file is almost certainly distributing malware.
So either A: Wait for the mod developers to update their mods to the current version or B: Downgrade your ETS2 version. SecretOne. Steam Community ETS2: Update 1.38 - The Truck Simulator Wiki Download Euro Truck Simulator 2 1.38
You can download a free trial for Euro Truck Simulator 2 on this page. To buy a full version of ETS2, please buy a Steam key here. Euro Truck Simulator 2 Euro Truck Simulator 2 Version history Officially, no
Yes and no. A save file created in a newer version (e.g., 1.49) work on 1.38. You will need to start a new profile or use a backup save from when you were on 1.38. Always back up your Documents/Euro Truck Simulator 2/profiles folder before downgrading. So either A: Wait for the mod developers