Registered spell checker plugin not showing in CODE docker UI

I installed a spell checker plugin into my docker with instructions I found from this forum etc.

unopkg add –shared voikko.oxt

And it seems to be registered also

unopkg list –shared

All deployed shared extensions:

Identifier: org.puimula.ooovoikko
Version: 5.0.2.20170827
URL: vnd.sun.star.expand:$UNO_SHARED_PACKAGES_CACHE/uno_packages/lu49370pwqg.tmp_/voikko.oxt
is registered: yes
Media-Type: application/vnd.sun.star.package-bundle
Description:
bundled Packages: {
URL: vnd.sun.star.expand:$UNO_SHARED_PACKAGES_CACHE/uno_packages/lu49370pwqg.tmp_/voikko.oxt/config.xcs
is registered: yes
Media-Type: application/vnd.sun.star.configuration-schema
Description:

  URL: vnd.sun.star.expand:$UNO_SHARED_PACKAGES_CACHE/uno_packages/lu49370pwqg.tmp_/voikko.oxt/voikko.components
  is registered: yes
  Media-Type: application/vnd.sun.star.uno-components
  Description:

  URL: vnd.sun.star.expand:$UNO_SHARED_PACKAGES_CACHE/uno_packages/lu49370pwqg.tmp_/voikko.oxt/config.xcu
  is registered: yes
  Media-Type: application/vnd.sun.star.configuration-data
  Description:

  URL: vnd.sun.star.expand:$UNO_SHARED_PACKAGES_CACHE/uno_packages/lu49370pwqg.tmp_/voikko.oxt/SettingsDialog.xcu
  is registered: yes
  Media-Type: application/vnd.sun.star.configuration-data
  Description:

  URL: vnd.sun.star.expand:$UNO_SHARED_PACKAGES_CACHE/uno_packages/lu49370pwqg.tmp_/voikko.oxt/Linguistic.xcu
  is registered: yes
  Media-Type: application/vnd.sun.star.configuration-data
  Description:

}

But Finnish language is not showing in the spell check lists and I was not able to find anything in the UI that would have changed after installing the extension.

Is there some way to debug this further?

Unfortunately, we don’t support extensions unlike libreoffice desktop.