I've read the introduction to the Wiki page, but I still don't get it: is there such a thing as regional elections in unitary states, for example Ukraine? President Zelensky appointed one governor, another — so it's how it's done in all unitary states (presidents appoint the heads of all administrative divisions), isn't it?
Even the UK is a unitary state on that Wiki map. So does it mean that the British PM unilaterally appoints the head of Scotland (sounds unlikely)? In other words, is there a link between whether a country is unitary and whether the constituents elect their governors and mayors?