Ukvi is not required for Australian language courses. You only need to take the general exam to go to Australia, and you don't need UKVI. UKVI can only be used in the UK.

Here is a popular science about what UKVI is-IELTS for UKVI is the IELTS test for British immigrants and visas, which is used for British visas and immigrants. The content of UKVI IELTS is the same as that of ordinary IELTS, except that there will be special remarks on the report card. It is the IELTS type of visa or immigration. The price is slightly more expensive than the ordinary IELTS, and there are fewer test sites and test time, but it can be used to apply for basic and language courses in the UK.