question How to block browser notifications (?)

You can disable browser notifications from your browser settings
For chrome, it's located in website parameters > notifications

First part will be all sites blocked, followed by sites you authorized to send you these notifications


Gube

I use Firefox for privacy. You can even modify Firefox for better privacy. There are several sources on the internet for Firefox preferences hacks. Because Firefox is open source. You can freely modify it with no limit. I would never use Chrome.

I'm using chromium-based brave browser, and an option to disable site notifications is right into its settings.

Pure chrome/chromium is a spyware:
https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)

In 2020, it may be good idea to debloat brave as well:

- block connections to analytics.brave.com via hosts file for example (set it as having 127.0.0.1)

- disable "brave rewards" which would also disable all its notifications

- disable at least some, if not all, brave-specific extra features (not needed, potential privacy issues, replacing G with B...). And, the built-in adblocker is a joke (unfortunately), too many ads missed.

- install and carefully configure uBlock Origin add-on for real adblocking

- install decentraleyes add-on

Firefox has Ublock origin, decentraleyes as well. It has tons of privacy addons. Enabling encrypted dns queries require only a few clicks on Firefox. Firefox has duckduckgo and wikipedia in its search engines list to choose. Firefox is the default browser on many linux distros.

https://privacysavvy.com/security/safe-browsing/most-secure-browsers/
(Just without Edge, due to its authors...)

https://peter.sh/experiments/chromium-command-line-switches/
--disable-notifications ⊗ Disables the Web Notification and the Push APIs.