As Wendy said, a playstand away from the cage that is a lower height than you are goes a long way...
"Height Dominance" is a misnomer, but the behaviors are very real. They don't so much become dominant when they are higher than you, but you are putting them in a position where they are difficult to control, and they are smart enough to know that. Right now, this bird is not trained well enough, or bonded enough, to be trusted in a position where you cannot control him.
On top of the cage, they know they can misbehave and get away with it. So the bird goes to the top of the cage, and plays the "can't catch me" game. (Because it's fun, and because he may be right!) Get something that makes you taller than the cage, i.e. a step stool, and tell the bird to step up nice, and mean business! (Because he will keep doing it until you put a stop to it.)
Like toddlers, the more they misbehave and get away with it, the more they misbehave PERIOD... you reinforce the bad behaviors every time they get away with it. And before you know it, you've trained them to behave badly. Then you have to UNTRAIN those behaviors, which is considerably harder, and involves significantly more "macaw testing."
When they know it won't work, they don't do it.
Like a little kid that runs away when you tell him to come here. If you go over there and pick him up - no only is that "come here", it's also "you will obey me when I tell you to do something."
You raise a macaw the same way... with love and positive nurturing guidance, discipline, and boundary setting.
Then, even when they are up high, you tell them to come down, and they know you mean it, they will.
(Or in the alternative, you can spend the next 20 minutes chasing him around the top of the cage, and get nipped or bit a couple of times for your trouble, before either getting the upper hand, or giving up on handling him. It's up to you!

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