Go to mega.nz: Open Firefox and navigate to https://mega.nz/. Click the Padlock Icon: In the address bar, click the padlock icon on the left side. Click on the Arrow: In the small drop-down menu that appears, click the small arrow to open a more detailed panel. Click "More information": This will open the "Page Info" window. Go to the "Permissions" tab: In the new window, select the Permissions tab. Find "Send notifications": Scroll down until you see the "Send notifications" permission. Select "Allow": Uncheck the "Use Default" box if it's checked, then select "Allow" from the drop-down menu.