The PS5 is deeply integrated online. If you attempt to install unsigned PKG files or connect to PSN with a modified console, Sony’s servers will detect the anomaly instantly. The result is a (also called a "Sony brick"). Your console will never connect to PSN again, killing online play, streaming apps (Netflix, YouTube), and game updates.
Consoles updated to the latest official firmware cannot run unsigned PKGs. The Role of Custom Tools Ps5 Pkg Games Download
There are official retail PKGs (downloaded directly from Sony's Content Delivery Networks) and custom/fake PKGs (fPKGs), which are modified versions used in homebrew environments. How PlayStation 5 PKG Files Work The PS5 is deeply integrated online