While working on my previous blog post, I came across another great feature you may not know about. Let’s say you use the Share menu, but opening the Page Actions menu requires too much navigation. You need quicker access!

To add an item to the address Bar, right-click on it and select Add to Address Bar.
To remove it, right-click on the item and select Remove from Address Bar.

http://ilias.ca/blog/2018/08/how-to-add-the-share-menu-to-the-firefox-address-bar/