Maybe you can get it shipped in if it doesn’t contradict your import regulations?
https://www.amazon.com/Ajika-Sabudana-Tapioca-Sago-Pearls/dp/B006GK58FK
If not - https://thesourcebulkfoods.com.au/shop/cooking/sago-small-pearl-tapioca/
https://www.amazon.com/Ajika-Sabudana-Tapioca-Sago-Pearls/dp/B006GK58FK
I found it on amazon, apparently it's used in Chinese and Indian food and in New Guinea. I'm in America, so I don't know what your ethnic markets look like there in Australia. But an Indian or Chinese grocery store would be my first place to look. I also don't know how much it would cost fo order on Amazon, but there it is! Good luck and let me know how the dish turns out!!