Because this is a multi-part RAR archive, you cannot use "part03" in isolation. You must have (e.g., part01, part02, etc.) in the same folder to successfully extract the game.
Follow the on-screen prompts to choose your installation directory. Monster.Hunter.World.Iceborne-PARADOX.part03.rar
: Ensure all numbered parts of the archive are downloaded and placed in a single directory. Because this is a multi-part RAR archive, you