Serial Number

A redemption code is used to get a serial number.  The redemption code may only be used once.

See here:

https://helpx.adobe.com/download-install/kb/find-serial-number.html

https://helpx.adobe.com/download-install/kb/redemption-code-help.html

What OS and version of Elements are you using?

This is a user-to-user group.  We have no way to help you with serial number issues.   If you have Elements 2021 or 2022, I suggest you try contacting Elements support. You can start a chat session by clicking on the blue Contact Us button under the Support menu at Adobe.com. Or you can contact Support by telephone using the numbers listed here: https://helpx.adobe.com/contact/phone.html.

For further information about redemption codes see this Helpx Article.