If you are looking for a standalone installation (common for players with low-end PCs or those wanting a specific legacy build without owning the game on Steam), users often search for "Mediafire" or "Modland" links.
Support was added for ownable Schwarzmüller and Krone trailers for DLC owners. Euro Truck Simulator 2 1.35 Download
The "temporary_1_35" option does not appear in the Steam Betas list. If you are looking for a standalone installation