From the manual:
When connecting the device to a USB 3.0/2.0 Type -A
port of the computer, you will need the included USB
cable and AC adaptor
How much power UR22C actually requires?
USB3.0 spec says that ports can deliver up to 900mA (Ports with charging capability, can provide more, usually between 2-3A, 1,5A by the spec),
so by the looks of it, it probably requires more than 900mA.
But manual does not say anything about 5V AC adaptor rating, which should be used with UR22c.