Russia has made a lot of claims about the nazification of Ukraine (Why Russia invades Ukraine). While it is not clear what exactly is meant by that (apart from calling Zelensky a neo-nazi and making false allegations of a genocide)
Summary: There are extreme right-wing groups in Ukraine as in many other countries as well. However, some militant and armed groups enjoy greater exposure as they were an essential part in the Revolution of Dignity in 2014 and in defending the Ukrainian borders against Russian army and pro-Russian militant fighters.
The support or power in the country of “nazi”-like groups are however very limited: Less than 3% of the population voted for the political party, the support is in general very low and anti-semitism is significantly lower than in any other country in the region.
Russian Ukrainian War 