Metal for Accelerating Ray Tracing - load OBJ or SCN file

I am trying to load a SCN or OBJ asset that has gemotry and textures into following Apple example code:

https://developer.apple.com/documentation/metalperformanceshaders/metal_for_accelerating_ray_tracing

I didnt find anywehere that I could link SCN files into Scene. How can I do that?