Here is a little trick that I have learned the hard way – When the locked money cabinet key is not wanting to turn – firmly push in all the drawers below the cabinet. I’m not sure why exactly, but the lock will not turn if the drawers are not firmly closed.
If the lock is still wonky – you can just put the money in the cabinet without locking it and leave a note on the buildingmaintenance Slack channel for staff the next day.