Since you can't buy one, you can "adopt" or support them through official conservation channels:
Kiwi are flightless, nocturnal birds native only to New Zealand. They have the second largest egg per body weight of any bird. National Zoo Facts and threats to kiwi - Department of Conservation buy a kiwi bird
They require large amounts of space to roam and a specific diet of soil invertebrates (like worms and grubs), making them incredibly difficult to maintain in a home setting. Since you can't buy one, you can "adopt"