Create a message rule.

Check the box next to "Send a different message depending on the guest’s
preferred language."

Create a “default” message. This message will be sent to all guests if a
preferred language is not specified or if you don't have a message in their preferred language.

Choose the languages you’d like to write translated messages for from the drop-down menu under the word "Languages".

To edit each translation, select the language from the drop-down menu under the word "Message" then add your translated message in that language.

Click the “Save” button in the bottom right-hand corner.