To actually install and run FPKG files, you need a jailbreak environment. Two primary tools dominate the scene:
for the latest jailbreaks (e.g., 11.00)
While raw ISOs often require a disc-based workaround or emulation to launch, a properly installed PKG file functions 100% independently of any physical media. PKG Files in Retro Emulation: The PS2 Classics Conversion ps4 pkg roms better