If you export as an FBX , the materials will be imbedded with the mesh.
Import the model into Unity then extract the textures into the Unity assets folder. Create a new Material in blender with the same name and assign the textures that you extracted.
I think the model will pick it up automatically if it has the same name, if not, just drag and drop the material on the model.
That’s a short and possibly not complete answer. It’s late here and I haven’t done it for a while so the details are a bit foggy right now.
