Importing environments from Unreal Engine or Unity to the Isaac Sim

Hi,
I am trying to build a pipeline for generating synthetic data with the specific given stereo camera configuration in different environments (I am interested in recording RGB, depth, and instance segmentation images). I have been able to build the given stereo camera configuration in the Isaac Sim and record data in the default environment (i.e.warehouse_with_sensors ).
However, I do not know how can I import different environments (e.g. from Unreal Engine 4 or Unity) into the Isaac Sim and record synthetic data from them with the camera configuration that I already have. Can someone help me with this issue?