As NSXGB mentioned, the Koyo Rad would be delivered with the bottom/upper plugs with the rubber seal installed on each of them.
Also, there should be 4 x bolt attached to the rad body for holding the rad fan shroud.

Once received, please flush the radiator well.

Based on the feedback seen on here and on Prime, you may want laying it flat, fill it up with water and leave it to monitor for tiny seepage around the welding.

Never experienced after installing so many of them but recent feedback on Prime suggests potential welding issue causing tiny seepage but not all of them.