– provided it comes from a legitimate source.
When you launch a new game for the first time, Steam or Epic will run this to "prepare" your environment. ue4prereqsetup-x64.exe
Third, advanced users or system administrators may run it manually to repair a broken installation. If a game crashes on startup with a missing DLL error, manually executing the ue4prereqsetup-x64.exe found in the game’s directory can often resolve the issue without a full reinstallation. It is, in effect, a targeted troubleshooting tool. – provided it comes from a legitimate source