Sims 3 expansion reddem code not working

Hello,

I have recently downloaded the Sims 3 again on my computer from at least 15 years ago. I downloaded the EA app and I am missing my Sims 3 Ambitions expansion pack. I entered the redeem code (since I have the CD Rom game) on the app and it says it was already used but I only remember having one EA account from years ago. All of my games were always originals and never purchased used. What can I do to get my redeem code to work so I can add it on?