(the boss of Depths II) at least once on that save file without mods active.
There are three primary ways to install mods for Repentance, and your choice will depend on where you're getting your mods and which version of the game you're on.
If a mod requires you to use the console ( ~ key), you may need to enable it by opening the config.ini file in Documents\My Games\Binding of Isaac Repentance and setting EnableDebugConsole=1 .
The traditional mod folder is located in your Steam installation directory. The full path is usually: C:\Program Files (x86)\Steam\steamapps\common\The Binding of Isaac Rebirth\mods
Before installing any modifications, you must meet two essential conditions to ensure your game functions properly and your progress counts.