Lakka is a pre-configured Linux distribution based on LibreELEC that comes with RetroArch installed. Lakka is primarily for single-board computers (SBCs) such as the Raspberry Pi.
Because Lakka uses RetroArch under the hood, the instructions are generally the same as RetroArch. By default, the Lakka BIOS directory is
Lakka has a
roms folder at
/storage/roms/ that is used by default: