Visit the official site of the repacker you used (e.g., FitGirl, DODI). They usually offer "Language Packs" as separate, optional downloads. PCGamingWiki:
Crucially: Avoid any file named “Setup.exe.” A genuine will be a .7z or .rar archive containing folders like CookedPC and Localization . Sniper Elite 3 English Text Files Download REPACK