https://brave.com/blog/mozilla-ppa/

I’m using vertical tabs since 4 years ago and to do so installed Tree Style Tab (https://tinyurl.com/y5gr4dyn)

Also has to disable horizontal tabs create or update the file chrome/userChrome.css located at your profile with

#TabsToolbar {
  visibility: collapse;
}

and add the setting toolkit.legacyUserProfileCustomizations.stylesheets with value true (use about:config)

Just updated my blog post with a link to original docker file 👆

There was no Docker support until three weeks ago. The author added it and I helped with some other missing aspects, mainly support for linux/arm64 (Raspi 4)

Also this repository contains an easy way to create your own image, upload to your own repo (mine is at https://hub.docker.com/repository/docker/bitman09/hrconvert2/tags?page=1&ordering=last_updated) and kubernetes support