A Director Penalty Notice is the ATO’s way of holding you personally liable for...

https://zulu-wiki.win/index.php/How_Do_I_Confirm_Whether_a_DPN_Has_Been_Issued_by_the_ATO%3F

A Director Penalty Notice is the ATO’s way of holding you personally liable for company PAYG, GST, and SGC debts. The 21-day clock starts the moment it is issued, so ignore it at your own risk