Hi Shinsuke

There is some documentation on the Localization service here:

https://our.umbraco.org/documentation/reference/management/services/localizationservice

In terms of an example, I use it in my DictionaryItemKeySearch dashboard, to save an updated dictionary item translation:

https://github.com/marcemarc/tooorangey.DictionaryItemKeySearch/blob/master/tooorangey.DictionaryItemKeySearch/tooorangey.DictionaryItemSearch.Api/Controllers/DictionarySearchController.cs

but also If you are creating dictionary items from scratch for an import then the following should work as an example:

 var ls = ApplicationContext.Current.Services.LocalizationService;    

//create a holder for the item's DictionaryTranslations

List<DictionaryTranslation> _translations = new List<DictionaryTranslation>();

 //the constructor for a DictionaryItem requires the Umbraco language object and value of the translated text                       
 //so get the language object, eg from Iso Code                            
var language = ls.GetLanguageByIsoCode("fr-FR");

// here we create a french translation for our item and add it to the list    
DictionaryTranslation dt = new DictionaryTranslation(language, "bonjour le monde");                           
 _translations.Add(dt);

     //get or create a DictionaryItem, (passing in the Dictionary Key)                           
IDictionaryItem di = ls.DictionaryItemExists("HelloWorld") ? ls.GetDictionaryItemByKey("HelloWorld") : new DictionaryItem("HelloWorld");

 // set the translations created above    
di.Translations = _translations;

 //now save the dictionary item and translations to Umbraco    
ls.Save(di);

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