Rather than altering configuration files, these options are fully supported natively within the game menus:
While older titles in the franchise like Call of Duty 4: Modern Warfare allowed players to easily trigger the command console using the tilde key ( ~ ), Infinity Ward changed its stance during the original Modern Warfare trilogy. If your goal is to input custom commands, bind layout configurations, or display real-time performance diagnostics, there are alternative workarounds depending on your specific version of the game. The Classic MW3 (2011): Activating Configuration Overrides
There is for the 2023 version of Modern Warfare 3 how to enable console in call of duty modern warfare 3
It is that attempting to force a developer console (devmap) or using unauthorized console commands to gain advantages in modern Call of Duty games can lead to:
: Never attempt to use "console enablers" or trainers in online multiplayer for any Call of Duty title, as these are treated as cheats and will result in an account ban. How to enable the dev console for SP MWII - Steam Community Rather than altering configuration files, these options are
When you launch the game normally, these commands will be loaded from the configuration file, enabling the developer console.
Good luck, and have fun experimenting with the wonderful world of console commands. How to enable the dev console for SP
: Use the official Activision Support page to troubleshoot performance or connectivity issues. Modern Warfare 3 (2011 Original)
Alternative Environments: Dedicated Servers & Third-Party Clients