Hello! My son is 2.9 years old. He doesn't eat food at all; he used to…

Hello! My son is 2.9 years old. He doesn't eat food at all; he used to eat at least pasta, potatoes, and rice, but now he only wants dry snacks like cookies, wafers, and the like ??‍♀️. He even refuses to eat children's sausages now, though he used to like them. He doesn't accept any vegetables. He only eats apples and bananas for fruits, and that's it. He drinks water fine. Other than that, there are no complaints. He just refuses to eat normal hot food. He has never accepted soups at all. He only eats mashed potatoes, and that's it. Maybe he needs some vitamins to boost his appetite? Has anyone tried this?