This series of photos shows how are made Xiaomi Aqara relays. The device used on the following pictures is a LLKZMK11LM.
On the following, you can see that the pin 3 and 4 are connected. When you receive the device, a wire is already mounted between these pins.
This small independant PCB contains the JN5169 microcontroller, the button and the LED the antenna connector and a 16 ways connector for communicating with the relays. On this picture, you may see the in-factory programming connector footprint.