gpio_shutdown in rpi desktop

rpi4 using bookworm desktop I'm using dtoverlay = gpio-shutdown to send a shutdown signal, and when i short GPIO3 to ground I get a shutdown dialog on my screen. Is there a way to make it initiate the shutdown instead of popping up the menu?

Im not sure but I think that changing dtoverlay = gpio-shutdown is the wrong place to change how shutdown behaves in the desktop environment.

I'm looking for an option for a hardware shutdown - I have an off delay set up, and I want to send a shutdown signal for a graceful shutdown before the power is cut

The option gpio-shutdown is sending a "shutdown" signal to the OS. And your issue is probably related to the OS or more the desktop. I use the gpio-shutdown solution to shut down Pi3, Pi4 and Pi5s and I dont have your issue as I uses the Light OS where I don't get the question.