I check the received model

There are a lot of references, the model I received is well stamped ZD06.

I put batteries

This model is equipped with a very practical AAA battery system (not supplied).

I launch the Zigbee pairing

I switch Zigbee2MQTT to pairing mode. 

The pairing starts.

The Open/Closed contact is well-functioning.

Clearly the information on the batteries goes up.

I'm going to Home Assistant.

I can find my equipment there

It is perfectly integrated (in TS0203)!