Claude finished product number invalidates old SK to prevent account theft:

✅ After logging into the webpage, click on the personal avatar at the bottom left, and select "Settings".
✅ In the pop-up settings window, switch to the "Account" tab.
✅ Find the "Log out of all devices" option and click it.
Or at the bottom, find other devices besides your own, click the three dots on the far right, and terminate other sessions.