its quite easy to find out what one you need, just download what they used to make it (Ren'py) to look at the code to find out which one will trigger it, or you can use UnRen.bat in order to see what flag values changes. i looked at the code of the game and there is 14 flag values and depending on how high each one is, it will give you an ending or an option for 2 or so endings.