The key that identifies the text to use for the action button in the alert panel.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- watchOS 6.0+
This property identifies the text to use for the button to open your app. Specifically, it contains the name of a key to look up in the app’s
Localizable file, the value of which is used for the button title.
Specifying a value for this property is optional. When its value is
nil, the alert panel triggered by the push notification contains only an OK button to dismiss the alert. When its value is not
nil, the alert panel contains one button to dismiss the alert and a second button to open your app.