The one thing you need to be sure of doing, as I mentioned in a previous post above, is right-clicking on the note to examine it, so that Martin knows what it is. (This is the note that you used the pencil on to reveal the code.)
Then it's all about speed after you use Barbora's ID card on the machine to get the green light. You really don't get much time here to click the pencil note on the machine while the light is still on.
"Bleat, Watson -- unmitigated bleat!" ~ Sherlock Holmes