Computer Configuration > Administrative Templates > Microsoft Edge > Content settings
Both
HKLM\Software\Policies\Microsoft\Edge
Allows you to create a list of url patterns to specify sites that are not allowed to display notifications. If you don't set this policy, the global default value will be used for all sites. This default value will be from the 'DefaultNotificationsSetting' (Default notification setting) policy if it's set, or from the user's personal configuration. For detailed information on valid url patterns, see https://go.microsoft.com/fwlink/?linkid=2095322. Example value: https://www.contoso.com [*.]contoso.edu