Place the config file in the same folder as the GUI.
: The final step compiles these assets into an installable .pkg file. Firmware Compatibility (4.21 and Beyond) custom pkg file for ps3 ps2 classics 4 21 bully
Open PS2 Classics GUI and select your Bully ISO. The tool will convert it into an ISO.BIN.ENC file. Place the config file in the same folder as the GUI