How do I use different models present in sitl_gazebo/models for PX4 SITL simulation in Gazebo?

Hey Guys,
I hope you’ll are safe and doing well,

I wanted to ask how do I use the different models like plane, iris_depth_downward_camera, etc present in the location PX4_Autopilot/Tools/sitl_gazebo/models in Gazebo simulation?

I realised simply passing the model name as an argument to vehicle does not work; it leads to many different errors like saying that it could not find the jinja.sdf file for that particular model (and that file in fact really does not exist for many of the models instead of some standard ones like iris, vtol etc.)

I am trying to use the launch multi_uav_mavros_sitl.launch which in turn uses the launch file single_vehicle_spawn.launch. Any help, leads and resources would be appreciated, TIA.