Wix-billing-backend createInvoice function

Hello everybody,
I recently created a backend function that uses createInvoice function of wix-billing-backend module.
When this function is called from a jobconfig cron, invoice is not generated in french ( local language ) but in english?
An idea?
Thanks by advance for your help.

Make sure that the language is set to French in the configuration or parameters of the createInvoice function. Double-check the documentation of the wix-billing-backend module for any specific instructions on how to set the language for invoice generation.

Thanks for your interest but not really useful!
I’ve ever triple checked my local language and no option exists for createInvoice function about language generation!