Use VoiceOver to navigate notifications on Mac
Notifications appear in the upper-right corner of the screen. Depending on how options are set in Notifications preferences, you receive notification banners and alerts.
Banners are visible on the screen only briefly. When you receive one, VoiceOver says the name of the app (such as Mail) and a brief description (such as your name and the subject line of the email), but the VoiceOver cursor doesn’t move to the notification.
Alerts remain on the screen until you take an action. When you receive one, VoiceOver says Notification Alert while the VoiceOver cursor automatically moves to the notification; the cursor remains there until you take an action or navigate elsewhere.
Note: VO represents the VoiceOver modifier.
Navigate in a notification: Press VO-Right Arrow or VO-Left Arrow. When you hear the action you want to take (such as Close, Reply, Snooze or Later), press VO-Space bar to select it.
You can also open the item, such as an email message, by pressing VO-Shift-Space bar anywhere in the notification.
Navigate to a notification alert: If you navigated away from an alert before taking an action, you can return to it by pressing VO-F1-F1 to open the Application Chooser. Next, press VO-Down Arrow until you hear Notification Centre, press VO-Space bar to select it, press VO-Down Arrow until you hear the notification you want to read, then press VO-Space bar to select it.
You can view pending notifications in Notifications view of Notification Centre. To open Notification Centre, press VO-M-M to jump to menu extras in the menu bar, press VO-Right Arrow until you hear Notification Centre, then press VO-Space bar.