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

https://wiki-legion.win/index.php/Superannuation_Guarantee_Charge:_How_SGC_Links_to_DPNs_and_Why_You_Need_to_Move_Now

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 the notice is issued