Setting default language and region for new documents


I’m running Nextcloud with OnlyOffice.

I have the following options set in /var/www/nextcloud/config/config.php:

  'default_locale' => 'en_AU',
  'force_locale' => 'en_AU',
  'default_language' => 'en',
  'force_language' => 'en',

But I notice that when I create a new .docx file inside Nextcloud and open it with OnlyOffice, the default language is English (United States).

Is there an option to set forced default language for newly created files?

Thank you.

To clarify, I’d like these options to be set in a new document by default:

I’ve tried changing the contents of /var/www/onlyoffice/documentserver/web-apps/apps/api/documents/api.js to be:

DocsAPI.DocEditor.defaultConfig = {
        type: 'desktop',
        width: '100%',
        height: '100%',
        editorConfig: {
            lang: 'en',
            region: 'en-AU',
            canCoAuthoring: true,
            customization: {
                about: true,
                feedback: false

And then running sudo supervisorctl restart all but this didn’t work… All new documents created in Nextcloud still default to English (United States) spellcheck and document language…

Any other ideas on what I could try?