I'd just stop at a Wal-Mart and buy a $5 paper license. You can get a refund form, but they charge $5 for processing ... so that's a mute point.
Maybe take a photo of your computer screen with your cellphone or use the "print screen" function on your computer, showing the license info (along with the written info) and take the chance that you won't get checked ... ??
It's your call .... but, for another $5 & piece of mind, I'd go the Wal-Mart route.