How to properly prepare HDRI map asset for FAB?

Hello! I have prepared an HDRI map and would like to publish it on Fab com. But I ask for help in understanding some points:
The requirements for publishing such content state that there must be at least 5 HDR Texture cubes. Does this mean that I cannot publish only one HDRI map? Or it’s about some other parameters?

I also received this requirement when making a listing: “Maps must have their lighting built”. Does this mean that I need to add the HDRIBackdrop plugin with my HDRI map to the asset?