How to power up the LTE hat on Raspberry Pi 4 without using any USB cable?

I stack the LTE/3G hat on the raspberry PI 4, then power up the PI, the PI is powered up,
but no LED light on the LTE hat, when I login to the PI, both lspci and lsusb didn’t see this LTE module.
I could not figure out how to power it up when I stack it up, if I unstack it, and connect it through the uSB cable, the hat is powered up.


please try to press PWRKEY for 0.5 sec