He tried to climb down the chain but it is kind of small. I started out holding the bucket and letting him eat treats out of the bucket then I held the bucket just far enough away that he could not reach it but he could reach the chain and I let him pull it. Then I hung it down just far enough that he couldn't reach the bucket edge even if he was hanging down from the perch by his feet. Once he got the idea to grab the chain instead of the bucket, I kept making the chain longer until he had to pull it up more than once.
You know how they like to transfer things from their beak to their foot to work on them. He just figured out to grab it with his beak move it to his foot and then grab again with his beak.
Peaches has devised another version of this trick where Turbo pulls up the bucket and she hangs down and grabs the treat before the bucket makes it to the top.