Web push notifications currently do not work on Apple iPhones, iPads, etc. using the default Apple Safari web browser.

For notifications to work here, the site needs to support being a Progressive Web App, which means setting up a web app manifest for the board.

https://developer.mozilla.org/en-US/docs/Web/Manifest

While this is necessary for push notification's on iOS, it's also just good to have in general. Even if you don't wanna use push notifications, it's still a better experience on iOS when users add a site to their home screen. Without a web app manifest, it's just a bookmark. But with this manifest, the site opens and function's like it is its own full-screen app, not something running in Safari.