supabase auth.getUser always returns null

hi guys, trying to get current user in getServerSideProps with next.js but it's always returning null.

import { supabase } from "../lib/supabase";

const {
      data: { user },
    } = await supabase.auth.getUser();

import { supabase } from "../lib/supabase";

const {
      data: { user },
    } = await supabase.auth.getUser();

supabase auth.getUser always returns null - Supabase