To be fair, they're (understandably) under martial law which has been extended in 90 day increments since 2022 with parliamentary approval. Elections aren't to be held under martial law per Ukranian law, and there have been ~~referenda~~ votes held among the Rada to determine if elections should be held, which failed.
Edit: referendum would entail direct democracy. That isn't what happened - it was just a vote by the legislature.