You can both customize the existing BSS locale and add a custom language pack to BSS.
To customize the existing BSS locale, save the customization file into the /k8s_data/locales/customization/ directory. For example:
root@bss-www-86688c5c6d-gcbqw /]# ls /k8s_data/locales/customization/ locale.ru.custom
Warning: To customize the default BSS locale locale.en, create a separate file with customizations, for example, locale.en.custom, and save it to the /k8s_data/locales/customization/ directory. Do not customize locale.en and do not save locale customizations to /usr/local/bm/conf/locale because your changes may be lost: when any of the BSS pods is restarted (by deleting it), the default locale locale.en is overwritten.
To install a custom language pack, follow Installing a Custom Language Pack to BSS.