Tahap 1 daripada 5 bintang

Added it to Thunderbird 60.5.0 and it did nothing at all

Ulasan ini untuk add-on (1.7) versi terdahulu. 

Have you tried to right click on the main toolbar and then choose "Customize"? Then you can move the buttons you want to the left of the first tab.

Without customizing this extension does nothing.