Cannot use server functions after build

const getMockupsSchema = z
  .object({
    cursor: z.string().optional(),
    limit: z.number().min(1).max(50).default(10),
  })
  .default({ limit: 10 });

export const getMockups = createServerFn({ method: "GET" })
  .middleware([authMiddleware])
  .inputValidator(getMockupsSchema)
  .handler(async ({ context, data }) => {
    const session = context.session;
    if (!session) {
      throw new Error("Unauthorized");
    }

    const conditions = [eq(mockup.userId, session.user.id)];

    if (data.cursor) {
      conditions.push(lt(mockup.createdAt, new Date(data.cursor)));
    }

    const items = await db
      .select({
        id: mockup.id,
        url: mockup.url,
        prompt: mockup.prompt,
        crawlingStatus: mockup.crawlingStatus,
        createdAt: mockup.createdAt,
      })
      .from(mockup)
      .where(and(...conditions))
      .orderBy(desc(mockup.createdAt))
      .limit(data.limit + 1);

    const hasMore = items.length > data.limit;
    const mockups = hasMore ? items.slice(0, -1) : items;

    return {
      mockups,
      nextCursor: hasMore ? mockups.at(-1)?.createdAt.toISOString() : null,
      hasMore,
    };
  });

installHook.js:1 Failed to "whatever_we're trying_to_do": Error: [
  {
    "expected": "object",
    "code": "invalid_type",
    "path": [],
    "message": "Invalid input: expected object, received undefined"
  }
]
    at Object.deserialize (main-a-LFmG3r.js:10:99362)
    at BR (main-a-LFmG3r.js:12:15180)
    at Ft (main-a-LFmG3r.js:12:16825)
    at _R (main-a-LFmG3r.js:12:13457)
    ...