FINGERPRINT SEN0348 PROBLEM WITH EXTERNAL INTERRUPT

Hi, I am new to fingerprint sen0348, I wish I could call it with the IRQ from an external interrupt but I am not successful, I am using an arduino nano and I have the IRQ set to pin 3 ... I was researching the library a bit and noticed that the IRQ acts in parallel with detectfinger, but if I want to put the arduino to sleep I can't wake it up and I don't want to use a button for it, I just want the fingerprint to wake up my arduino when it detects a finger