You might want to let us know what camera you are talking about, and better still, show us a photo of all sides, top and bottom.
Old folder manufacturers placed their releases in many different places. Some were bumps under the leather on the top or side, some were a seemingly unrelated screw. It just depended on who designed the camera. On some old ones, you might see what is the release, but find it is damaged.
If you know where the release is, and it doesn't seem to work, that would be useful to know as see photos of.