There is currently no working PlayStation 4 emulator that can run commercial games properly. Projects claiming to be "PCSX4" or offering PS4 BIOS downloads are almost always scams, malware, or fake files . You will not find a legitimate BIOS for a non-existent emulator.
If you are looking for real PS4 emulation, these are the only community-verified projects currently in development: pcsx4 bios download
claim to offer downloads for Windows, macOS, and Android, legitimate PlayStation 4 emulation is still in its early stages through open-source projects like There is currently no working PlayStation 4 emulator
Even if we ignore the fact that PCSX4 is a fake emulator, downloading a BIOS file from an unauthorized source is a terrible idea for three reasons: pcsx4 bios download