If your bike did not come with the nacelle originally you’ll need different front turn signal mounts for the top part as that is the fitting that the nacelle screw to for the top half and then the bottom mounts as well which are only for the nacelle mount and serve no other function.
Parts 15-18 for the lower mounts (17, are the mounts, the rest are the associated hardware. Quantities required listed next to the price)
Parts 3 and 4 are the different turn signal mounts which also serve as the nacelle mounts. You may need the screws and washers for the nacelle itself (parts 12 and 13) depending on who you buy it from and if they include it. It'd be worth asking if who you buy the nacelle from will include the mounts and hardware with the sale.