files_pdfviewer Apache 2.4 locale.properties not accessible, unable to load translation files

files_pdfviewer
Apache 2.4 , default_type application/octet-stream; directive is disabled.
http://ip/apps/files_pdfviewer/js/pdfjs/web/locale/locale.properties not accessible, unable to load translation files
I configured addType application/octet-stream .properties in website directory nextcloud/data/.htaccess
But it doesn’t work, how to deal with it? Thanks!