It is possible to add other languages provided that the translations are validated by WhatsApp.
Using the classic mode:
In classic mode, messages are sent to the buyer in the language determined by WhatsApp.
In order to display the payment page, the payment gateway determines the language based on the international code included in the message.
If the language cannot be determined, the payment page will be displayed in English.
Using the echo mode:
In echo mode, messages are sent to the merchant in the language of the shop.
The ISO code can be transmitted in uppercase or lowercase letters.
Example of syntax:
amount currency language
If the ISO code transmitted in the message is valid but not supported, a specific error message will be returned. The merchant can override the default language by specifying the ISO code to use in the message.