Air France tries hard to hide the fare structures, but their Russian subsite provides an overview:
https://russia.airfrance.com/en/info...fare-structure

According to that, international travel in the classes R, T and L is not refundable. Which is funny, because when doing a test booking for the future on the same route as a flex economy, AF shows e.g. fare code RKX57RMZ which would indicate class R (unless the fare structure have changed again since 2020). Are fare classes country of booking dependant as well? Or maybe their page is just not updated.