I have made a working plugin for the Konami Code for RPG Maker (works with MV and MZ for sure. I haven't tried it with other versions.) that you can activate at anytime during gameplay, this to activate a control switch (by default Switch 3, because that's what I needed it for). Use it for whatever, doesn't matter.
It is free for anyone to use, commercial or otherwise. No restrictions.
Up, up, down, down, left, right, left, right, B, A (X, Z on keyboard).