They're calling Zelensky a dictator because his term was originally scheduled to end in 2024 unless re-elected, and there were no elections since the beginning of the war.

The problem with this assertion is that Ukraine has "no elections under martial law" written into the law. Zelensky himself actually wanted to do some kind of election to reinforce his mandate while his support was still very high, but there was serious concern from the liberals about those plans on the basis that any election held under martial law, with large numbers of people mobilized to fight, 20% of the country occupied, and many millions of refugees unable to vote, would hardly be free and fair. Their pushback scuttled any plans for the parliament to amend said law.