Best way to specify type for rpc call response data in TypeScript?

const { data } = await supabase.rpc(
  'upsert_subject_with_observations',
  // ...
);

// Property 'id' does not exist on type 'string[]'.
console.log(data?.id);

public.upsert_subject_with_observations(
    in observation_ids uuid[],
    in subject subjects,
    out id uuid)