Apple Ukrainian Hardware Keyboard: Input Source
Apple has recently begun selling standalone hardware keyboards for Ukrainian, a picture of which is below.
The correct input source for this keyboard is "Ukrainian" as found in MacOS 12. The input sources called "Ukrainian" and "Ukrainian PC" found in earlier MacOS versions will not match output with what is printed on the keys. People wishing to use the new Apple Ukrainian keyboard with earlier MacOS versions can get a copy of the Monterey input source here.
Since the Apple keyboard is new, Windows Ukrainian keyboards have often been used in the past. Unfortunately the Input Source which these require (Ukrainian PC) was removed in Monterey. People who want to use a Windows Ukrainian keyboard with Monterey can get a copy of Ukrainian PC here.