How to configure the Interrupt of NFC Grove

Hi everyone,

I have the NFC grove 1.1. It is working in terms of reading / writing.
Now, I am trying to implement the Interrupt function, can someone please help me.

Board: Arduino Yun
Communication with Grove: HSU via digital pin 10 and 11
Interrupt: I physically connected a wire from IRQ pin in the grove to digital pin 2.
Code: I followed the tutorial from NFC shield ([])

However, there is no change on the IRQ pin. I also measured it with oscilloscope.

Any idea on how to use the IRQ?