Questions about ros-gopigo - nodes, urdf, and other

That GitHub repo seems to be indicated for ROS support so I was reading the code. I was not sure why the gopigo3_node.py talks about the servo which as I understood is an optional device.

Another question is that the .launch file doesn’t launch the other nodes. Is the intention that we modify that launch file and add the other nodes or is there some other intention?

Another question is that there’s no urdf for the robot. Is that somewhere?

Thanks!