How to exchange Runed crest for Gilded

Hey, new casual player here with a dumb question. I heard once you get to ilvl 658 you can exchange Runed crest for Gilded but vendor isn't showing me the option. Do I need every slot at 658?

Btw I have two crafted gears at 675 not sure if they count or whether I should upgrade a gear to 658 from that slot.

Thanks in advance.