When a user uses a donation form in French, all communications including the email confirmation need to be in French. There needs to be a way to translate the confirmation email in the email designer so that French people are receiving the same user experience as English users.
Currently the transaction details will be in whatever language the donor saw the form in (English or French.) Any custom content you added will only be shown in the language you created it in. If you expect to have donors with both languages visiting your form, for now we recommend any custom content be entered in a bilingual manner.
We are evaluating a future feature to translate custom content within the emails, stay tuned to future product update briefs for more details.