@abc599472824 When you buy a game or a pack through Origin, it's automatically added to the Origin account that bought it. There's no product code, and nothing to register. So the pack should already be in your game library. Open it, click on the Sims 4 icon, select More > Expansion Packs, scroll down to Eco Lifestyle, and click Download, if it's not already installed.
To buy a game for a friend, you need to select the gifting option instead of the Buy Now option on the product page. There's no way to transfer a pack from your account to someone else's, even if this was supposed to be a gift. You can try contacting EA customer support and asking for help:
https://help.ea.com/en/contact-us/
But there's no guarantee that a support rep will be able to do anything.
