To bring CAD models into Unity, it is usual to need an additional tool such as PIXYZ or CAD Exchanger.
These tools allow not only to convert the format to be compatible with Unity but also to optimize the geometry so that the performance of the application in real time is adequate.
PIXYZ has become an entitled package for Unity Industry and is included in the com.unity.industry.toolkit package, please see the next guide in order to install it in your UnityProject