Full policy: https://klarsono.com/en/confidentialite/ (French: https://klarsono.com/fr/confidentialite/)

Klarsono collects, only when you use it: your e-mail address and name (sent by Google when you sign in, to keep your account and your minutes), and the text of the subtitles or the audio of the video you are dubbing (sent to our API and to our speech providers to be translated, transcribed or voiced, then discarded — never stored). No browsing history, no ads, no advertising trackers, nothing sold to anyone. You can export all your data and delete your account in one click from your account area at klarsono.com.

Politique complète : https://klarsono.com/fr/confidentialite/