How can I fix this MarketplaceService code so it will purchase on the player's account?

The ID is from a model, my Samsung Galaxy Alpha model.

local assetId = 186631891

script.Parent.ClickDetector.MouseClick:connect(function(player)
	Game:GetService("MarketplaceService"):PromptPurchase(player, assetId)
end)

I'm not sure what I need to add to it.

It automatically does this. You just need to make sure you award the player.