Right click the shortcut and click 'Properties'.Create a shortcut to CK3 (right click and select 'create shortcut').To open Crusader Kings 3 in debug mode without Steam: How to open debug mode with the raw game file This will deactivate debug mode when you relaunch the game. If you want your achievement system activated again, you'll need to remove this text from the launch options menu in the same way you added it in. Add '-debug_mode' to the launch options.
To open Crusader Kings 3 in debug mode for the Steam version: Watch on YouTube How to open debug mode with Steam