Free Redbox DVD Rental Code + Letter from Santa

I used the link provided and it did take me to the very awesome site of doing a Santa letter (free of charge!) but I never saw any option to get a free redbox code, nor did it come in the email I got that had the Santa letter inside. On a separate but not huge note, the email with the letter also comes with a pdf showing the front of an envelope addressed to your child from north pole and with stamps and postage meter markings on it and everything. Cool, but how do I use that?? Am I supposed to print it out and somehow fold it to look like an envelope maybe? Or cleverly glue it to front of a regular envelope and hope child doesn’t notice? Just curious if anyone made use of that additional thing