(SOLVED) Textures are completely white on kart (QUESTION)

I'm trying to make a custom kart but I can't get the textures working properly. I didn't make the vehicle model, so that's why that has a working texture, but the character I modelled is completely white. I can't export as a kart for some reason, so I have to manually export as a .spm. If anyone knows how to make the "Export STK Kart" button work too that would be great
(and that could be the problem).
