Where to download SketchUp Desktop 2023.0.2 and revert back from 2023.1?

If on Windows, you should do a clean uninstall of 23.1 including app data files or you might run into issues.

You can get the installer here: https://download.sketchup.com/SketchUpStudioFull-2023-0-419-179.exe

On Mac, installer here: https://download.sketchup.com/SketchUpPro-2023-0-418-179.dmg