Article D7121-36 of the French Labour Code

To benefit from continuous annual leave, in application of article D. 7121-31, the employee must send the paid leave fund the certificates he has received from his employer or successive employers. This transmission is made at least fifteen days before the date on which the employee takes his leave.
After verification, the fund will pay the employee the amount of compensation to which he/she is entitled upon presentation of proof of social security registration.

Original in French 🇫🇷

Article D7121-36

Pour bénéficier du congé annuel continu, en application de l’article D. 7121-31, le salarié transmet à la caisse de congés payés les certificats qu’il a reçus de son employeur ou de ses employeurs successifs. Cette transmission est faite quinze jours au moins avant la date à laquelle il prend son congé.
Après vérification, la caisse verse à l’intéressé le montant de l’indemnité à laquelle il a droit contre remise d’une pièce justifiant son immatriculation à la sécurité sociale.