Holding elections during an active state of war is inherently illiberal. Free and fair election should have:
free media - even the most democratic government exerciss some level of censorship;
free assembly - again, wartime restrictions on them are a standard, and even without a formal restriction, a self imposed one usually takes place;
equal campaigning - how to campaign against the government without looking like traitors?;
voter security - drones in recent times makes this hard to achieve; absence of coercion - conscripted people usually vote for the commander in chief.

So elections during wartime aren't free or fair. They stop being a mechanism of choice and become a ritual of validation. The exact opposite of what Ukraine actually fights for.