How to download Photoshop elements 2023 on iMacOS? I have bought it 2 years ago and now wanted to use on iMac and unable to find the Photoshop elements 2023.

First place to start is by looking on your Adobe account:

https://helpx.adobe.com/download-install/apps/download-install-apps/creative-cloud-apps/download-previous-versions-non-subscription-apps.html

If you by chance bought PSE 2023 thru the Mac App Store, then go to Apple>App Store, then in the lower left corner click on your name and should see any apps that you previously purchased.