Create index in DESC order

Consider this schema:
export const contactFormSubmission = pgTable(
'contact_form_submission',
{
id: serial('id').primaryKey(),
name: varchar('name').notNull(),
email: varchar('email'),
subject: varchar('subject'),
message: varchar('message').notNull(),
showInGuestbook: boolean('show_in_guestbook').default(false),
submittedAt: timestamp('submitted_at').defaultNow(),
},
({ showInGuestbook, submittedAt }) => ({
guestbookIdx: index().on(showInGuestbook, submittedAt),
}),
);
export const contactFormSubmission = pgTable(
'contact_form_submission',
{
id: serial('id').primaryKey(),
name: varchar('name').notNull(),
email: varchar('email'),
subject: varchar('subject'),
message: varchar('message').notNull(),
showInGuestbook: boolean('show_in_guestbook').default(false),
submittedAt: timestamp('submitted_at').defaultNow(),
},
({ showInGuestbook, submittedAt }) => ({
guestbookIdx: index().on(showInGuestbook, submittedAt),
}),
);
The index of the query is expected to serve this query only, so I wanna have it in DESC order.
db
.select()
.from(contactFormSubmission)
.where(eq(contactFormSubmission.showInGuestbook, true))
.orderBy(desc(contactFormSubmission.submittedAt));
db
.select()
.from(contactFormSubmission)
.where(eq(contactFormSubmission.showInGuestbook, true))
.orderBy(desc(contactFormSubmission.submittedAt));
I.e. the goal:
CREATE INDEX contact_form_submission_show_in_guestbook_submitted_at_index
ON public.contact_form_submission
USING btree
(show_in_guestbook DESC, submitted_at DESC);
CREATE INDEX contact_form_submission_show_in_guestbook_submitted_at_index
ON public.contact_form_submission
USING btree
(show_in_guestbook DESC, submitted_at DESC);
The issue is desc() doesn't seem to do any when declaring the index. How am I supposed to specify DESC in this case?