Add on in toolbar to go direct to downloaded pdf in Finder [MAC]

Until a few months ago I had a small icon on the right hand side of the toolbar with the URL in it - after I downloaded a pdf to a file in Finder I could click on that icon & it took me straight to the downloaded pdf file in Finder.
It was very convenient.
It avoided having to go to Finder & find the recently downloaded pdf file myself.
I don’t know if it was an add-on or some other type of link: I just had the icon in the toolbar.
Does anyone know what it was & where [or how] I can get it again?

I got a reply from Mozilla Support:
Firefox auto-hides the Downloads button on the Navigation Toolbar by default.
The Download button should appear on the Navigation Toolbar once you open the Customize window.
If you do not see the Download icon then click the Restore Defaults button to reset the layout in case you previously have moved this button.
Once you see the Download button in customize mode then left-click this button to see the current auto-hide state and toggle its setting.

It worked.