@camjrp You need to install it first, then follow the documentation on how to configure your es_systems.cfg so that it starts RetroArch with the right cores on the SNES/PSX games. As an example, RetroPie uses something like retroarch -L <PATH_TO_CORES>/snes9x_libretro.so %ROM%" to start RetroArch with the right Libretro core for the SNES system.