says code not found when i try to redeem stalker bundle edition

If you're talking about the Reclaim your game page, you can try opening a support ticket. Send them photos of the physical game and serial number, maybe the proof of purchase if you still have it, and they might be able to do something.

However, that page states, If your game key should be eligible but doesn't work, you can always try again in the future. . But it was last updated in 2017 and it's been removed from the footer links on the site.