I didn't quite get what you meant so I'll try covering the most.
Across game versions in the same platform?
You shouldn't really have to do anything. On PC (Not sure about Mac or Linux) the saves are stored in a external location from the game's own folder so they're automatically loaded when you open the game again.
Also if you're using the itch.io launcher to play the game then it's even better since you can use it to update without redownloading the entire game.
On Android it shouldn't be a problem if you can properly update the app (Most installs fail when you don't have enough free space).
If not, you might need to backup your saves using a file manager that can access the folder (SolidExplorer is recommended).
Across different platforms?
Like, from PC to android. You need to find the save location and just copy them to the other.
WHERE ARE SAVES LOCATED ON ANDROID? Android/data/com.domain.corruptedkingdoms/saves
WHERE ARE SAVES LOCATED ON PC?
PC > Local Disk (usually C:) > Users > USERNAME > AppData > Roaming > RenPy > CorruptedKingdoms-1547378918
WHERE ARE SAVES LOCATED ON LINUX?
~/. renpy/CorruptedKingdoms/
WHERE ARE SAVES LOCATED ON MAC?
~/Library/RenPy/CorruptedKingdoms