Blur was never officially released for the PlayStation 4. It was a PlayStation 3, Xbox 360, and PC title from 2010 (developed by Bizarre Creations, published by Activision). Therefore, there is no official PS4 PKU (update) for Blur .
Because there is no official PS4 version, the community uses files. These are often created by: Installing PS4 Games, DLC & Updates on the 9.00 Jailbreak blur ps4 pkg upd
or find a functional PKG update for a homebrew environment required more than just a download; it required the "PS4 Package Sender" and a console running specific firmware. Blur was never officially released for the PlayStation 4