Was you able to solve the problem using the docker image? I’m facing the same problem.
I’m creating a custom docker image, where I installed the collaboraoffice*pt-br but I’m missing something since the UI still in English.
FROM collabora/code:22.05.10.2.1
USER root
#Instala pacote de localização para o português da Collabora
RUN apt update
RUN apt install -y locales locales-all collaboraoffice*pt-br
ENV LC_ALL pt_BR.UTF-8
ENV LANG pt_BR.UTF-8
ENV LANGUAGE pt_BR.UTF-8
#Volta o usuário para o da imagem base da collabora/code
USER cool
EDIT: Just to clarify: The docker image collabora/code:22.05.10.2.1 already come with all language package installed, so there is no need to perform an apt install -y collaboraoffice*pt-br.
EDIT2: In the browser, I can see the pt-BR localization files being downloaded, but the UI still in English. Maybe the Collabora Code is hardcoded to English only?
Solution: Adding lang=pt-br to the URL solved the localization problem for me.