Browser extension does not appear in Firefox

I did play around with that before, but did not see that on the pulldown on the gear, there is a choice "Pin to Toolbar". In fact that is what does the trick.

Between the last time I loaded Firefox and today, Firefox has updated in such as way as to reset to initial defaults. I don't know why that would be. Every update in the past preserved all the settings, including extensions, bookmarks, etc. Today I had to reinstall the 1P tension, as well as import all the bookmarks. And probably more settings that I might come across remain to be done. Fortunately I don't use Firefox very often.