I give the guard at the window what he wants, but it doesn't work

Hint 1 of 6:

You need to get the orders stamped with an authorization.

Hint 2 of 6:

Did you get a blank stamp from the storage room with the laces?

Hint 3 of 6:

When officer drank the water, did you "TAKE Stamp" and get his stamp?

Hint 4 of 6:

Did you go back to fountain room and find the inkpad to right of chair?

Hint 5 of 6:

"USE stamp on inkpad".