Chromebook Crouton Debian xfce4 - Cannot change locale!

On the system described in the title, I am trying to change my locale to a UTF-8 one, in order to run the program Anki. However it won’t let me, the commands locale-reconfigure locale-gen and any locale-xxx/xxx-locale command doesn’t exist.

There was no locale.gen so I created one, it looks like this:

en_GB.UTF-8 UTF-8
LC_ALL="en_GB.UTF-8"

When I type in locale it says everything is POSIX except LANG, LANGUAGE and LC_ALL which are all left blank.

locale -a returns:

C
C.UTF-8
POSIX

I’ve followed the guide on debian wiki and many other guides, all of which involve the use of locale-gen or a similar command which I don’t have. I’ve also tried restarting with the new locale.gen, but that also didn’t work.