Try to find a keychain that looks like it, and extend the chain. You can use a plastic cup as a hoop by cutting off the very top part of the cup, making a ring. Alot of keychains have little ball shaped objects on them. Just make sure to remove the key-ring as his beak or claw can get trapped in. Or you can use a round button on a string.
Presently have six Greenwing Macaw (17 yo), Red Fronted Macaw (12 yo), Red Lored Amazon (17 y.o.), Lilac Crowned Amazon (about 43 y.o.) and a Congo African Grey (11 y.o.)
Panama Amazon (1 Y.O.)