When Sony released "PS2 Classics" on the PlayStation Store, they bundled individual PS2 games inside an official PS4 application wrapper (.pkg) containing a software-based emulator.
An icon ( icon0.png , recommended size 512x512) and a background image ( pic1.png , recommended size 1920x1080) to personalize your dashboard. Step-by-Step: How to Create a PS2 FPKG ps2 fpkg
Downloading random PKG files from the internet is risky. Malicious users can embed payloads that crash your console or, in theory, expose your network. Stick to trusted sources with active communities. When Sony released "PS2 Classics" on the PlayStation