Ukraine had elections for many years. Now it would be difficult to organise an election because parts of their country are illegally occupied by the fascist Russian regime.
Russia, unlike Ukraine, has not had a legitimate presidential election for years. Ballot boxes are stuffed in Russian "elections". Opposition politicians are either banned from running (e.g. Boris Nadezhdin) or poisoned by the state because they are deemed too much of a threat to the powers that be (this happened to Alexei Navalny).