Edit: Just looked and it looks like Joey is not a baby at all and is around the same age as Kiwi! See if putting him up higher (like the top of his cage or a tall piece of furniture) and targeting down lower will trigger his instincts. That's gotten Kiwi to attempt flight a few times. Not repeatable and scary for everyone involved, including a fairly serious head first crash.
I've tried numerous 'variations' of the "move perches farther away" technique with my stubborn amazon. He just gets frustrated and angry too. Unfortunately, he never fledged and at 19, I hold little hope he will ever really learn to fly. He does however like to hold onto my hand and flap his wings as we walk around to pretend fly. It's still good exercise and builds muscles. That could be another thing to try. Remember, when they are older and have never flown, they have underdeveloped flight muscles, flapping exercises really help build those muscles. Kiwi is hardly ever on my hand moving from point a to b where he isn't flapping his wings (just like if he were actually flying). Still, after years of those exercises, he STILL refuses to fly on his own.