Question - how can I unlock Helheim ?

Like the title said, i'm trying to do some Helheim run to have better gear. Im currently base lv61 job 28 (summoner to be) but everytime I go to the statue, it says the feature is unavailable.

Is there a specific quest I need to do to unlock it ?

Ive tried asking the question in the in game chat but i haven't gotten an answer yet.

Thanks