Is there any doc like protocol to describe the communication between micro-ros and micro-ros-agent?

I have SUB a topic from microROS site and micro-ros-agent print some message that shows everything is ok. But when I pub the topic from ROS2, the micro-ros-agent seems didn't Receive and Transfer it to Micro-ROS site. So I am wondering whether something is wrong when do SUB.

Thansk for any comments.