Uruz has the slot you can mount JD on, yes.
But it can't use it, because JD requires advanced powerplant.
The weakest powerplant that can supply JD is a battlecruiser one.
Neither Uruz can jump with a JD4 battleship (it's only possible for smaller transports - 3600ers and below)
It is not possible for any trader to jump solo, as the minimum power core required to operate the basic jd2 is 3,600,000 which is a Battlecruiser power core.
However since JDs use up 900 cargo, and require 360 MOX for one jump. This total space is greater than the cargo of any Battlecruiser without guns. Thus making it impossible for them to use it. So really only battleships can operate jump devices effectively