I have looked at his code and I havent found mistake - I would code it exact the same way tbh… you simply make
tappable minigame for all the buttons and the one that is correct you add + points.
And if the code has 4 digits you will have 4 tappable minigames one ater another and each will mark with the points the one correct number that should be tapped in that moment.
And if he has 4 point it means he inserted it correct - if he has not 4 points he didnt add the code in right order and will be brought on start.