Hirose’s datasheet and operating instructions for the part can be found here: DF60-series Catalog.
Hirose has confirmed that this part does not include M3 nuts, nor do they sell the nuts separately. You have to purchase them from a third party. Any M3 nut and screw should suffice, with the only concern being the length of the screw not exceeding the length of the panel by a significant margin. Here’s an example from the 2D drawing for reference:
Applicable Part Numbers
|DK Part #||Mfr Part #|