Item Model not loading

So for a while now I've been trying to add a custom item to minecraft via datapacks and resource packs. No matter what I do, I cannot seem to get the custom texture to load and it only displays as that purple and black square. I know the item file itself works because its fallback is set to the vanilla knowledge book model. The bug only happens when the item file's conditions are met. I've been stuck on this for over 2 hours, I need help 🙁