I would need more details on exactly which example you are running. If you are using the API docs, those are not full examples. Their code snippets won’t run without some work.
This tutorial works for me though, and is probably what you are looking for:
https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/tutorial_advanced_range_sensor_lidar.html#isaac-sim-app-tutorial-advanced-range-sensor-lidar