Firepit - Charcoal Coals Above Or Below Grill?

[2gbmum]

Hi, BBQ novice here. I've just bought a firepit which comes with two grills. An uppermost cooking grill and a lower 'charcoal' grill.

Do I put the coals beneath the charcoal grill in the belly of the firepit or on top of the charcoal grill?

There's about a 4" clearance below the charcoal grill into the bowl and the same distance above it to the cooking grill. No clue on assembly instructions!

Help please - it's a sunny day today and I'd like to get it fired up!

[hammerman]

You put them on top...the grill just gives good air flow under the coals and allows for ash to drop down