From ... https://www.gov.uk/exchange-foreign-driving-licence/y/yes/car-or-motorcycle/a-designated-country-or-territory-countries-or-territories-with-exchange-agreements-with-great-britain/ukraine
QuoteExchange a foreign driving licence
You can continue to drive in the UK without exchanging your licence for 12 months after becoming resident.
After 12 months you must exchange your licence to keep driving. You can exchange it up to 5 years after becoming resident, if it has not expired.
If your licence allows you to drive manual vehicles, you can usually exchange it for a UK licence that allows you to drive manual vehicles.
It seems that Ukraine has been added (late) to the list of designated countries - the "Pass me fast" website at https://www.passmefast.co.uk/resources/driving-advice/exchange-foreign-driving-licence is useful once you look over the glaring error that it does not list Ukraine!