When a Director Penalty Notice arrives, your 21-day window starts immediately....

https://spark-wiki.win/index.php/What_Should_an_Advisor_Do_When_Lodgements_Are_Current_but_Payment_is_Not_Possible%3F

When a Director Penalty Notice arrives, your 21-day window starts immediately. The difference between a lockdown and non-lockdown DPN comes down to whether your BAS or SGC statements were lodged on time