Missing H4-EAD receipt notice mail. How to avail auto-extension?

Dated: June 30, 2022
I think USPS has lost/misplaced my H4-EAD receipt notice. I raised query on their website and got response that they sent it on May 25, 2022 and cannot send a duplicate copy and to retain the email for future reference. In such case, how to get auto-extension?