Dear Dylan,
We are sorry to say that FoodBook only supports global attributes for a variable product, it does not support custom attributes.
Please check this article https://docs.woocommerce.com/document/variable-product/ to know steps by steps on how to create a variable product using global attributes.
Moreover, you could use the “Add Features” option https://prnt.sc/u1hic4 of FoodBook.
Best Regards,
ThemeLooks Support Team