On December 10, 2021, Apple finished the review of version 15.2.0 of PDF Notes S & PDF Notes C and they became Ready for Sale.
On December 9, 2021, I uploaded version 15.2.0 of PDF Notes S & PDF Notes C to App Store
PDF Notes S https://itunes.apple.com/app/id961336139
PDF Notes C https://itunes.apple.com/app/id1459073729
This version fixed the bug of keyboard shortcuts in iOS 15.