How can you make a player recieve money (Candy in my case) After talking to an npc?

i am building a trick or treat game but i do not know how or if it is possible to make a player recieve a random ammount of candy/money everytime they speak with an NPC, is there any to do that?

You can use the Dialog's InUse property to check when the conversation is over:

game.Workspace.Dialog:GetPropertyChangedSignal("InUse"):Connect(function()
	if(game.Workspace.Dialog.InUse == false)then
		--give the player candy
	end
end)