Redeeming an Apple software purchase

I purchased FCP in November 2021, knowing I would need it the next semester (i.e. now).

The email containing my content code etc. tells me to "simply" launch the Mac App Store and "click 'Redeem' found under Quick Links and enter your content code(s)."

I cannot find any menu, menu item, button, link text, or anything else labeled either "Quick Links" or "Redeem" in the App Store.

I'm running OS10.13.6 (the latest possible) on a 2015 Macbook Pro, and looking at App Store version 2.4 (658.2)

Any hints for me?