Log off Facebook?

Hi   !
You can turn off these notifications   (but not just for Facebook) :

Type in the address bar   about:config   (press Enter) (promise to be careful, if asked) Type and look for the preference : dom.webnotifications.enabled and set it's value to   false Type and look for the preference : dom.webnotifications.serviceworker.enabled and set it's value to   false

What kind of notifications is this about?

Do you see them when you are on the Facebook website or also when you do not have nay Facebook tabs open?

You can check the notification settings in "Tools -> Page Info -> Permissions"