Update to the latest version of Luma3DS by replacing your current boot.firm with the new one, then update your system. It is safe to update on most versions of Luma3DS but it's always best to keep your CFW up to date.
https://github.com/AuroraWright/Luma3DS/releasesHow can I find boot.firm file? Must I place the file in the root of my SD card?
The latest firmware is 11.13 and it is available worldwide. What makes you think there is no update for the 3DS in Australia?There is no 11.12.0-44 update for 3ds in Australia yet.
Is it just for the USA?
https://github.com/AuroraWright/Luma3DS/releases
You do have to place it in the root of your SD card. You can move it to your NAND if you want.
https://3ds.hacks.guide/finalizing-setup