https://support.mozilla.org/en-US/kb/installing-addon-thunderbird

For some reason my Tbird is not quite the same as the instructions for the add on mgr. I did not have a search box or the little gear logo that is shown in the instructions. However I did find when I dragged and dropped the file in the dark area on the left side of the pane it installed correctly. Thank you.

We need to edit that page to guide you to the "Extensions" tab to see the search box. Or in fact, any of the tabs, with the sole exception of the "Get add-ons" tab, which would be the natural place to start looking when you want to, er, get add-ons. :-(

Thanks again for the help, I couldn't have done it without you.