Open your emulator's directory and find the system or bios folder.
The file is widely considered the "ultimate" BIOS for PlayStation 1 (PSX) emulation because it wasn't actually pulled from an original 1990s console. Instead, it is the BIOS Sony specially optimized for the PSP’s PlayStation emulator in firmware version 6.60 . The "Extra Quality" Story psxonpsp660bin bios file extra quality
Which and operating system (Windows, Android, Steam Deck) you are using? Open your emulator's directory and find the system