DuckStation is a simulator/emulator of the Sony PlayStation(TM) console, focusing on playability, speed, and long-term maintainability.
A “BIOS” ROM image is required to start the emulator and to play games. You can use an image from any hardware version or region, although mismatching game regions and BIOS regions may have compatibility issues. A ROM image is not provided with the emulator for legal reasons, you should dump this from your own console using Caetla or other means.