Here's a small guide to the puzzle:

1. You'll find three pages with a number.
2. The three numbers give six possible code variations. For example, 1, 2, and 3, if combined, can make 123, 132, 231, 213, 312, 321.
3. Try each combination and click the door (after each one) to see if it opens.

❗ The code must be entered in the middle row on the lock, not in the bottom one!