1. Click the padlock icon in the address bar.

         Gray padlock - Firefox 70

  2. Click the arrow in the Site Information drop-down panel.

  3.  Click More information in the next panel to bring up the Page Info window. 
  4. Click the Permissions tab. 
  5. Under Send Notifications, choose a notification option: Always Ask, Allow, or Block. If your choices are grayed out, deselect the Use Default checkbox. 

   Alternatively, you can:

  1. Click the menu button and select Options.

        Fx57Menu 

  2.  Click Privacy& Security from the left pane. 
  3.  Scroll to the Permissions section. 
  4.  Click the Settings button to the right of Notifications
  5.  Select Allow or Block from the Status drop-down for any of the websites. 
  6.  Click the Save Changes button.