Since you aren't using discs, the updated v10.1 ISO is often patched to return to the PS2 Browser or OPL menu with the cheats "resident" in the system memory.

Launch the CodeBreaker v10.1 ISO through OPL or your preferred loader.

If you are running games via Open PS2 Loader, using the CodeBreaker ISO requires a specific "handshake" to work correctly:

Beyond just cheating, it acts as a robust memory card manager, allowing you to compress saves or move them to USB.

Unlike the cluttered menus of early cheat discs, v10.1 is snappy and organized by game title. How to Use CodeBreaker v10.1 with OPL

Press Start. The software will prompt you to insert a game disc.