Citizens & CMDNPC Trade

Hello there! I'm currently requesting help with a few of my plugins, all revolving around one: Citizens. I'm attempting to make a private Bed Wars server for a group of friends and I, and I'm working on the shops. In since I am completely naive when it comes to coding plugins, as well as the point that I am not spending money on a Bed Wars or a Hypixel plugin, I just need to fix this one issue.


I have it set so, in the shop, there are five categories.


I'm going to use the blocks category as an example. When you click on it, it brings you to another menu showing the corresponding items.



When I click on the wool button, it proceeds to give the player 16 wool. But, another systematic also takes an additional 4 iron ingots from their inventory. As you can see, it clearly works.



But, if I were to have no iron ingots, it would still give the player 16 wool and just show an error that the player does not have 4 iron ingots. So, one command works, but the other doesn't... And I have no idea how to make if statements. Hence, why I'm using CMDNPC and ChestCommandsGUI.


If anyone could help it'd be greatly appreciated!