@LuizNeto5454 I take it you never registered the game yourself? Please check your Origin account to see whether you already own Supernatural: sometimes people double-click and submit a product key twice, and the first one goes through while the second one returns an error. The CD key you see in Steam is almost certainly for Supernatrual, not the base game—Steam stopped providing base game keys for Sims 3 early this year.
If your Steam and Origin accounts are already linked, that could also explain why your CD key reads as used.
If you don't have Supernatural in your Origin account, you could try contacting Steam support with a screenshot of your CD key being rejected. A Steam support rep might be able to issue you a new code. Or you could contact EA customer support with screenshots of the game in your Steam library; someone from EA could manually add the game to your Origin library.
https://help.ea.com/en/contact-us/