Edit textures - AI MODEL GENERATED

I created a 3D model using D5’s AI. It works very well, but I’m not able to change each material individually on the object. This is important because I want to test new material combinations.
In the objects, it appears as an imported .fbx.
Is there any way to locate this FBX file?

Hi @tannotalieri the generated model is in .d5a format and does not support applying different materials.