When you create a new push or in-app campaign, the editor allows you to create notifications in several languages. The default language is the fallback language used in your push and In-App campaigns.
You can add languages, clicking on "+". Batch will automatically send the message in the right language to every targeted users.
1- If you are sending a campaign in one single language, you can write your push directly on the first tab "Default".
2- If you are sending a campaign written in different languages, choose one default language, then create many messages in other languages.
Batch will deliver the message in the default language if you don’t have a message in the language of a user.