Does the iOS/iPadOS version of safari support push api standard with service worker?
As for 2023, IOS 16 will support web push notification. That is announced on their official blog:
https://webkit.org/blog/13878/web-push-for-web-apps-on-ios-and-ipados/
But it seems only web apps that have been added to the Home Screen can request permission to send push notifications.
old answer:
iOS 12, 13, and iOS/iPadOS 14 still doesn't support these features:
So many requests from the community for these features but Apple don't want to hear it. Maybe they think these features have a bigger chance to be unnecessary exploited(spam, etc). And also maybe they want to force developers to create the native application rather than the progressive web application.