If you’re on Android, cheats are enabled by default, so you don’t need to do anything. You can find them in Main menu -> Preferences -> Extra tab and in Sonya’s menu during gameplay.
If you’re on Windows / Linux / Mac:
To activate cheats first exit the game if it’s open, then create a file named non est pax impiis (any extension will do, for example .txt) in the same folder where the game’s executable file is located (Innocent Witches.exe). For MAC the path is Innocent Witches.app/Contents/Resources/autorun/ (make sure that you’ve right clicked the Innocent Witches executable file, the one with the game’s icon, and navigated into the apps contents). After that new options will appear in the Extra section in the game’s preferences, which will allow you to, among other things, unlock the memories. Additionally, during the playthrough a new menu will appear in Sonya’s interface, which will allow you to add gold and change stats.