is not clear in the document, https://nwidart.com/laravel-m.

 $langPath = base_path("resources/lang/modules/blog");

if (is_dir($langPath)) {
    $this->loadTranslationsFrom($langPath, "blog");
} else {
    $this->loadTranslationsFrom(__DIR__ ."/../Resources/lang", "blog");
}

which file is the code in the document to be added to?