After a quick look, I think the materials are too complicated for 3DObject, 3DObject only supports simple diffuse textures.
Looking at the model it has transparent textures and PBR alpha blend, metallic roughness, etc. which 3DObject does not support.
One possibility is to bake your textures down to a diffuse texture. This can be done with different modeling tools like blender. There is a little description of this on the video on the itch site.