wiki-js/client/graph/admin/locale/locale-mutation-save.gql

mutation($locale: String!, $autoUpdate: Boolean!, $namespacing: Boolean!, $namespaces: [String]!) {
  localization {
    updateLocale(locale: $locale, autoUpdate: $autoUpdate, namespacing: $namespacing, namespaces: $namespaces) {
      responseResult {
        succeeded
        errorCode
        slug
        message
      }
    }
  }
}