language?

Thanks for reaching out. The plugin uses the default language as applied in a users General settings, or an individual users language settings. While the French language is not fully 100% translated yet you may be encountering the same issue as describe in the below GitHub issue, with some already translated strings not fully rendering when using the plugin:
https://github.com/google/site-kit-wp/issues/2171

We an keep you notified here with any updates on this, we hope to have translations fully rendering soon.

@dragondefeu76 we released a fix for the issue referenced in the most recent version 1.21.0. Could you update and let us know if your experience has improved?

@dragondefeu76 since we have not heard from you, I am marking your topic as resolved. Feel free to open a new topic if you have further questions.