You could have used the Sketchfab exporter addon for Blender which would take care of the model and all the materials.
But, importing it the normal way can be done with an .obj and the associated .mtl for the materials to go with it. I haven’t done it this way, instead using the addon, but this is how it is done according to this post: BAC: "My Desk" - Feedback, WIP, Inspiration and more!