Send multicast message by using MQTT

Hi friends, just a quick question. I am planning to use MQTT to send multicast message to the devices created in Chirpstack platform. However, I am unable to find out topic template for setting multicast message. The guide found from website is about using MQTT multicast function in REST API.

Appreciate very much if someone can share relevant resource or information.

Thanks!

This is (currently) not possible.