I am trying to make a script that prevent players to click an iron sword that doesn't have custom model data. But the script below will always cancel the clicking no matter the clicked sword has a custom model data or not. I wonder what could be wrong in the codes?

Script Version: 2.6.3

Minecraft Version: 1.19.3

Full Code:

Code (Text):

1. on inventory click at iron sword:
2.     send "1!"
3.     if event-item doesn't have custom model data:
4.         send "2!"
5.         cancel event

Other Useful Info:
Server Version: Purpur 1.19.3-1900

No addons using

Have you tried searching the docs? Yes.
Have you tried searching the Forums? Yes.
What other methods have you tried to fix it?
I also tried the example of On Inventory Click event in the doc:

Code (Text):

1. on inventory click:
2.     if event-item is stone:
3.         give player 1 stone

and it don't work for me too. Nothing happens when clicking a stone.