How to use the os-locale function in os-locale

const setSystemLocale = (dispatch, languages, translations) => {
  return osLocale().then(locale => {
    console.log(`System Locale: ${locale}`);
    setActiveLanguageSafely(dispatch, locale, languages, translations);
  });
};

templateOption,
      themeSet,
      type,
      allowLocalFiles:
        this.args.allowLocalFiles ?? this.conf.allowLocalFiles ?? false,
      engine: this.engine.klass,
      globalDirectives: {
        description: this.args.description ?? this.conf.description,
        image: this.args.ogImage ?? this.conf.ogImage,
        theme: theme instanceof Theme ? theme.name : theme,
        title: this.args.title ?? this.conf.title,
        url: this.args.url ?? this.conf.url,
      },
      html: this.args.html ?? this.conf.html,
      jpegQuality: this.args.jpegQuality ?? this.conf.jpegQuality ?? 85,
      lang: this.conf.lang || (await osLocale()).replace(/@/g, '-'),
      options: this.conf.options || {},
      pages: !!(this.args.images || this.conf.images),
      watch: (this.args.watch ?? this.conf.watch) || preview || server || false,
    }
  }

export function getLocale() {
    const { RUNG_LOCALE } = process.env;
    return resolve(RUNG_LOCALE ? RUNG_LOCALE : osLocale());
}