The Steward’s Golden Chest is one of Bastion’s daily treasure hauls in World of Warcraft: Shadowlands. You’ll need to offer a Ripe Purian to the NPC mentioned by Elios during the quest called Fruit of the Gods. Your target changes each day, and one of the possible stewards is named Ioanna.
Ioanna is located at 25.8, 33.4, close to the shoreline in Steward’s Rest, in the northwestern portion of Bastion. A member of The Ascended, Ioanna will be standing next to a statue that bears a striking resemblance to her. Make sure you have brought one of the Ripe Purians with you for Ioanna; if you don’t have one in your inventory, Ripe Purians are found throughout the entirety of Bastion, and there should be one resting on a table at 37.5, 33.1. Head due east from Ioanna’s position and you should see it, unless someone else has already stolen it for themselves.
Once you give the Ripe Purian to Ioanna, she will reward you with the Steward’s Golden Key. You can then head back to the Steward’s Golden Chest, which will unlock with the key and reward you with whatever daily treasure is waiting inside. Along with the daily loot, this will award you with a Medallion of Service if you have the Kyrian selected as your covenant.