If a guest contacts you, but you don't have the message templates in the language we would prefer to send messages in, we would use templates from your fallback language.
By default, the fallback language is set to English (that is 97% of conversations we process), but you can change it following the steps below:
Go to Settings under your account.
Click on Preferences.
On the new page, click on the Guest Experience section on the sidebar.
Click on the dropdown list next to Fallback language and click on the language of your choice.
Click on the Save changes button.