You must be an Australian resident and in Australia on the day you claim Youth Allowance.
Keep in mind, newly arrived residents may have a 104 week waiting period.
If you’re a non-protected Special Category visa holder, and have lived in Australia for at least 10 years without a break since 27 February 2001, you may be able to get Youth Allowance for up to 6 months. This can only happen once.
If you qualify this way, the newly arrived residents waiting period won’t apply.