I didn’t notice the picture you posted.
Someone simply removed the address block from the address toolbar.
Each piece of a toolbar in FF is modular, you lost that module.
right click on any empty space in that toolbar, click “Customize...” then select the “restore default set” then click “done”.
You should be good to go.
Will remember that for the future.
Yours was the only suggestion I hadn’t tried (I didn’t see it before I re-installed FF).
Used Revo Uninstaller and totally removed Firefox. Then re-installed it.
We lost some bookmarks but other than that all went well.
Thanks to everyone for their knowledge and tips!