Allow addon to run in Private Browsing mode

In order to block websites that are opened while using Firefox's Private Browsing mode, this add-on requires special permission. Firefox usually asks users to give the add-on permission when the add-on is first installed. However, the permission can be granted or revoked at any time.

To change this permission, press the menu button (three lines button) in the top-right corner of Firefox and select "Add-ons". The add-on list should have "Website Blocker" on it. Click the Website Blocker add-on. This will open the add-on description. Below the description is the "Run in Private Windows" section.

If you want websites to be blocked in Private Browsing mode as well as regular browsing mode, select "Allow". If you only want websites to be blocked in regular browsing mode, select "Disallow".

The Website Blocker add-on does not track your browsing activity, so there's no privacy risk if you allow the add-on to run while you are in Private Browsing mode.