Here is one on Klook for Mongkok pick up:
Dongle as in wifi router for all purpose - by USB thingy you mean a wifi stick.
This is what I got - cost ca HK$500 - a hotspot dongle:
let’s not get into the etymology of widgets, etc...;-)
Last edited by jdf21st; 09-01-2019 at 08:26 PM. Reason: Greater clarity
Cool! Good luck, and happy travels!