Are you horrified that any website would even ask to send notifications to your desktop? Would you like this pop-up to never appear again? Then:
- In Firefox, visit the URL about:config and if promted, say you do want to void your warranty
- Filter using webno
- Double click dom.webnotifications.enabled (changing the value from the default true to false)
Thanks to this guy for the Firefox info.
- In Chrome, in the top-right, click the 3 vertical dots (the More menu) and select Settings
- At the top, search notifications
- Expand Content settings, then Notifications
- Toggle Ask before sending to Blocked
Chrome info from the Google Support article.