In general, web push notifications give the option to allow or block them, but this is not the case for a website that I visit. I tried allowing them and then editing them in Options>content>Notifications but apparently I can only see or delete rules there.

Given that the website (pretty maliciously) denies the ability to block those notifications, what can I do? Is the web push notification permission list stored somewhere so I can edit it and add this website to Blocks?