Debug Console - JamesWilko/Payday-2-BLT GitHub Wiki

The debug console is loaded via the BLT injector by detecting a developer file. This method is used to ensure that the console window is always the first window to appear when it is enabled, instead of appearing after the game is loaded, due to the base mod loading the console via lua instead of being hard-coded into the DLL itself.

Enabling the Console

Go to your mods folder.
Create a new text document and name it developer (developer.txt).
The console will now open when the game launches.