Hello Lemonray,
First of all, I advise you to make sure about the date of the opening of your rights before submitting your "feuilles de soins". You can do so by contacting your "caisse primaire d'assurance maladie (CPAM)".
If your CPAM confirms that your "feuilles de soins" can be sent in order to get refund, you will have to send them by post after putting your social security number on the top and sign them.
For more information, you can have a look at this webpage from ameli.fr : "La feuille de soins papier".
Have a nice day.
