iPacky supports the native Shopify locales (this is not Shopify locations). Meaning that you have your website translated into several languages.

iPacky will be able to print the packing slips (not picking lists) in the languages declared in Shopify locales.

The language used on the packing slips is the language on the customer. So this will be the store language that the customer selected when placing the order.

If you have enabled locales in Shopify, you should be able to see the button Localization texts in Settings→Packing slips. If you don’t see that button, please contact iPacky support because your store might lack some access scopes in Shopify.

In Localizations texts, please add the supported languages from the list. Then you edit the header texts for each language. The default texts if no match is on the main Settings→Packing slips screen. So if your store supports Japanese and English, just add the texts for Japanese, and the customers that do not match the Japanese language will be using the default texts.

In Settings→Packing slips, there is also a checkbox: Use product translations. This means that it will use the customer locale to show the product names on the packing slips.