where do i add power steering fluid to my car. on 1995 Oldsmobile 98

i have looked for a resevoir but can't see anything, do i have to take it in to a shop?

Asked by for the 1995 Oldsmobile 98
Locate the power steering pump it is at the rear of the engine compartment at the passenger side driven by a fan belt.Adjacent to it is a square reservoir with a screw on cap that is where the fluid goes. The system should not leak fluid, investigate the source of the leak.