Such a GREAT game! I really want more of this. This game is like watchdogs 2but without that fancy fake hacking stuff. I didn't say that the devs copied Watchdogs2 I'm saying that this game has a lot of things that it needs. [SPOILER]--> It's a real challenge trying to find all the codes and guiding the drones with security cameras. All the other hacking sim I played is just 100% code or 100% shooting. This game has the perfect balance. I really need part 2 maybe with more commands and machines. I finished the game using the conference room's window because couldn't find the code for the maintenance door. I really want to know how to get it.
I'm not sure if you mean the maintenance access panel codes, but they're at camera 10, covered by the mug. You need to use a drone to push the mug off, physically, and break your neck to read the codes upside down. I'd recommend the notepad for remembering the codes! Then you can just sneak the briefcase out of the office via the 2 maintenance panels. Then it's smooth sailing from the kitchen, to the closet! Hope this helps!