Passive Keyless entry clone?

Hello All,

I have a Easyguard car alarm with passive keyless entry - The typical car alarm remote that alrms have acts as a keyless entry fob - but passive. What I mean is when I get within about 20 feet of the car, the alarm disarms and the doors unlock. No need to press a button.
So I’m not sure HOW this works, ie is the alarm remote traansmitting constantly, or is the car transmitting and when the fob receives the low power signal, ithe fob then tranmits… or what.

Any way to determine this and make the FZ emulate it?

Here’s the device. https://amzn.to/3RmNtYH

Thanks!