Where is the key card for the elevator located?

[Chunga Changa]

I can't move through the level with the warehouse because I found only 3 key cards and can`t reach other areas of this level. I`m tired of looking around again and again. Share the locations of the key cards please. There are no guides and videos about it.

[Revannia]

I don't remember the exact cards that were found in each location but there are 2 in the Sorting room area and one in the little room connecting workspace to control room, if I'm not mistaken.