On the right side of your Firefox address bar, you should see three dots. If you click that, this displays all of the options that are available for the address bar. The Bookmark This Page option should be listed there. If you right click on it, you can select the Add to Address Bar option.

Hope this helps.

See also:

• https://support.mozilla.org/en-US/kb/bookmarks-firefox

Tried Mr. Branton's solution, but "delete this bookmark" was the option, nothing about adding it to the address bar. The solution from cor-el was pretty much the same.

Do you mean the menu that drops from this toolbar button:

That menu does not have "Bookmark This Page". However, you have several other options to bookmark the current page:

• In the address bar, click the star icon after the Page Actions menu button (•••) -- as mentioned by earlier posts
• In the Library menu (either from the main menu button or button) > Bookmarks > Bookmark This Page
• right-click a blank area of the page > star icon
• Keyboard shortcut: Ctrl+d
• On the optional top menu bar, Bookmarks menu (press Alt+B to open if you keep this bar hidden) > Bookmark This Page

Note the the article I mentioned above includes instructions to add the Bookmarks Menu button to the Navigation Toolbar and instructions to restore the star to the page action menu (three dot button in location bat).

• https://support.mozilla.org/en-US/kb/bookmarks-firefox

Can you give more detail about how you used this lost button and where it was located ?

If you try to add the button when you are on a page that you have already saved in your bookmarks, the button will be Delete this bookmark instead of Add this bookmark, but they are the same. If you right click on it, that's how you will see the Add to Address Bar option.