Good luck. I have tried and it did not work for me, but others have mentioned success.
You can try scanning from your monitor, but try making the picture not look like it is on a monitor
I also tried printing the receipt from Kroger website, but the header was different and they rejected it. I then cut out a header form a different receipt and laying it over the header from the printed one, and of course there is a noticeable line when I copy it.
I tried using a paper cutter after printing to make sure I had good lines, and this failed as well.
If the offer is still active, return and repurchase (and don't throw away the receipt)