Rated 5 out of 5 stars

I downloaded B6 but I am unfamiliar with the file type? How do I get that to work in Thunderbird?

Léirmheas ar leagan níos sine den bhreiseán seo (12.0.4).  Rinne an t-úsáideoir seo léirmheas ar an mbreiseán seo cheana.

NA
The file is an XPI which is just a zip container for the addon. To install go to Tool/Addons and then to the gear button. Choose Install Add-on from file and locate b6.

If you have issues please raise an issue in Github so we can look and interactively solve the problem.
(also reconsider review for a beta question...%-))
Cheers
Christopher