The iOS and iPadOS 16.4 betas that were seeded to developers today add support for web push notifications, a feature that Apple promised would be coming to iOS 16 back in June.
Websites that are saved as web apps to the Home Screen can send iPhone and iPad users Web Push notifications through the Push API, Notifications API, and Service Workers. A web app added to the Home Screen can ask the user permission to send push notifications, as described by Apple's WebKit team.
A web app that has been added to the Home Screen can request permission to receive push notifications as long as that request is in response to direct user interaction -- such as tapping on a 'subscribe' button provided by the web app. iOS or iPadOS will prompt the user to give the web app permission to send notifications. The user can then manage those permissions per web app in Notifications Settings -- just like any other app on iPhone and iPad.
Notifications from websites are designed to work exactly like notifications from other apps, showing up on the Lock Screen in Notification Center and on a paired Apple Watch.
Other new Safari 16.4 features include support for Focus for managing Safari Push Notifications, badge counts for website push notifications, third-party browser support for Add to Home Screen, and more.
Source: Macrumors