Rated 5 out of 5 stars

per Matti Koskelainen el mar. 22, 2021 ·

Works fine with Thunderbird version 78.

How to use?
-Open Preferences --> General --> Language --> Finnish --> "Toteuta ja käynnistä uudelleen". Job done.

This review is for a previous version of the add-on (78.0buildid20201019003438).