Language packs work on all three platforms. Note that the Chinese language pack is based on a quite incomplete Thunderbird localisation. Language pack XPIs need to be downloaded with "Save Link As..." and installed manually.
All binaries are for x64 systems. Sha256 sums available here.
Table of Downloads for version 91.13.1-bb37 (13 September 2022)
Version 91 is no longer supported. Please switch to version 102.