This replaces a file in the Engine folder and in the Win64 game exe, not very large from the original Steam version.
So that you can back up the folders or just replace them completely, you can later check the integrity cache to download the un-debug version again
it will only download again at a maximum of 210mb.

Copy the folder "DRAGON BALL Z KAKAROT" to "SteamLibrary\steamapps\common\" and replace everything it asks for
Now you can run the game from Steam and debug will be enabled everything will work.

Once you open the game it'll ask you what you want to go to, after you're ingame press \ or / to open the debug menu.