I wonder How to merge multiple PX4_SITL on Gazebo using ROS Multimaster_fkie

I’m trying to merge multiple PX4_SITL on single gazebo… using ros1

I’m trying to develop multiple uavs simulation in MultiROSmaster environment.
Each of PX4_SITL are running on each of virtual machine
So, I am using ‘multimaster_fkie’ for ROSmultimaster and ‘mavros_controller’ for offboard control.

but, i don’t know that multiple PX4_SITL model spawn on single Gazebo on another virtual machine…