You screenshot says you're trying to enter as a Conjurer (class). If you do have the Scholar (job), that should do it.

Jobs are: Paladin, Warrior, Dark Knight (*HW), White Mage, Scholar, Astrologian (*HW), Monk, Dragoon, Ninja, Samurai (*SB), Bard, Machinist (*HW), Black Mage, Summoner, Red Mage (*SB)
*HW = Requires Heavensward
*SB = Requires Stormblood