In my opinion, the undeniable horror of Russia's crimes makes it even more important to point out when Ukrainian forces do something bad as well, and to push back against it. Russia is overall committing far more evil than Ukraine, but if we have a mindset of "as long as we are less evil than the Russian government it's OK" then that leaves a lot of room for us to fall.

That being said: it's totally true that military forces aligned with Ukraine have shelled Ukrainian cities, in Donestk and Luhansk. Usually it is to strike at Russian military targets, but sometimes it is extremist factions like Azov who genuinely want to kill civilians and children. There is plenty of video evidence.