the 4 is for the code after in the before last room also you open the door in the whiteboard room
by hitting it with the hammer
hello dobsy the whiteboard was having issues while I was building the game for some reason it works
I hope you understand that I created this for a game jam in 3 days so I didn't have time to fix it
in the editor but not the final build also you actually need to hit the door with the x on it with a hammer or push it down
also about the keypad in the beginning next to the first door it says you cannot interact with buttons directly.