Custom `Yup` validation messages
See here for the original answer.
One way you can do this is via regex, by accepting any value that is not "none":
const NewUserSchema = Yup.object().shape({
createDate: Yup.string().nullable().required('Create date is required'),
boughtby: Yup.string().matches(/^(?!none).*$/, "Cannot be none").required("Cannot be none")
});