You don't need to manually transfer your saves - just install the new update on top of the old one and your saves will automatically transfer over :)
If you still want a backup, just to be safe, they're located in:
Android/data/com.domain.corruptedkingdoms/files/saves
NOTE: If you're running Android 11 or 12 then Google has hidden your data folder. To access it you need to connect your phone to your PC with a USB cable or use an app like Solid Explorer or X-Plore to give you access to the folder again.