You do not need a separate download link; it is accessible through the "Betas" menu in your game launcher: : Right-click Stardew Valley in your Library. Select Properties > Betas .
For handheld users, the compatibility version is often required to get the game running. Set Steam to the "compatibility" Install/Reinstall Stardew Valley in PortMaster. Copy the updated game files from your PC Steam folder ( steamapps/common/Stardew Valley ports/stardewvalley/gamedata folder on your SD card. Stardew Valley Compatibility Guide Stardew Valley Compatibility Version Download