Certificate expired in ver 1.3

I can not push notification because Knuff certificate has expired, could you update new certificate ?
Thanks a lot!

<img width="516" alt="Screen Shot 2022-06-06 at 23 42 44" src="https://user-images.githubusercontent.com/93649428/172206377-cc59cc68-92d8-4809-88fd-b589045c546e.png">

