@tn63050dr if you have just installed Elements 2023, you need to go to the Help menu and choose to Install Camera Raw . . This additional step for users of raw files is required because Adobe decided to reduce the download file size for those users who do not need Camera Raw.
I am assuming that you have an older Nikon camera and that ACR 14.4 which is installed with Elements 2023 is sufficient for your camera processing. If you have a brand new camera, you may need a later version of ACR. Check the links provided by Bob to see which version of ACR you need. Elements 2023 will install the very lastest version (ACR 15.1 as of the date of this post) if you follow precisely the instructions set forth in this HelpX article.
@Peru Bob Nikons use NEF files. 🙂