How can I get the rplidars' data from different uavs

[Hao-Po]

As title:
I tried to use the 【PX4-Autopilot/launch/multi_uav_mavros_sitl.launch】.
And sdf is【iris.sdf.jinja】.
I put the rplidar in 【iris.sdf.jinja】just like 【iris_rplidar】.
Now, the problem is when I use 【rostpoic list】
The topic with laser only 【/laser/scan】
I have 3 uavs but only one topic.
I want to split it to 3 topics, like /uav0/laser/scan, /uav1/laser/scan ...
how can I do this, thx.