Elements 2018: How do I get my serial # using a redemption code?

I'mrunning Windows 7 Pro Dell XPS 2015 computer.

I purchased this product New at a local Staples.

I just purchasedAdobe Photoshop Elements 2018. During the installation I'm required to type inmy serial number. This product doesn’t come with a serial number, I have a redemptioncode. I tried putting that in but it doesn’t take Letters, only numbers. Now what?Where is this serial number?