80s Apartment - Bathroom Ceiling Exhaust

I'm on the top floor of an 80s apartment with a flat roof, what is the feasibility of having a ceiling exhaust fan installed in the bathroom?

I currently have a window exhaust which isn't very efficient and is far from the shower so I'm looking at a better solution. The apartment have a flat roof without much eave space.

Can the ceiling exhaust be installed? If yes, which trade do I engage to do this?