Computer Configuration > Administrative Templates > Microsoft Edge > Content settings
Both
HKLM\Software\Policies\Microsoft\Edge
Set whether websites can display desktop notifications. You can allow them by default ('AllowNotifications'), deny them by default ('BlockNotifications'), or have the user be asked each time a website wants to show a notification ('AskNotifications'). If you don't configure this policy, notifications are allowed by default, and the user can change this setting. Policy options mapping: * AllowNotifications (1) = Allow sites to show desktop notifications * BlockNotifications (2) = Don't allow any site to show desktop notifications * AskNotifications (3) = Ask every time a site wants to show desktop notifications Use the preceding information when configuring this policy.