Led ceiling light has extra wires!
I'm having trouble finding an exact match on the Artika site, and the Costco site (as usual) does not list all the products found in stores. The products that I checked manuals on the Artika site have no mention of the other wires.

My hunch is that the thick black, thick white and copper ground wires should be attached to the matching ceiling wires, and that the other wires are for daisy-chaining to additional matching fixtures. Unfortunately, without a manual it is hard to tell for sure. I would try connecting just those 3 wires and cap (wire-nut) the thin wires for safety (each one separately) and see if that works.