Directly converting PS3 games into native PS4 PKG files is not possible
If you don't want to risk bricking your console or being banned from PSN, Sony provides official (though limited) ways to play older titles. PS Plus Premium convert ps3 games to ps4 pkg
Q: Is it legal to convert PS3 games to PS4 PKG files? A: The legality of converting PS3 games to PS4 PKG files is complex and depends on your location and ownership of the game. Gamers should only convert games they own and have the rights to play. Directly converting PS3 games into native PS4 PKG
Directly converting PS3 games into native PS4 PKG files is not possible because the two consoles use completely different system architectures convert ps3 games to ps4 pkg