You are able to run your referral campaign in a default language other than English. Please note that changing your default language will reset the templates of your emails & pages.
The latest list of available languages can be found here.
To change the default language.
Go to the Referral Program tab and select Language Settings
Under Language Settings, select the default language in which you would like to run your referral campaign in. If your store is running in multiple languages, you also have the option to select other languages from this page. You can find more about this here.
Click Save Changes.
Note: The text on your emails and pages will not be automatically translated to the selected default language. You can manually translate the texts by going to the Emails and Pages section and editing the theme you'll be using for your store.