I'm not really sure what they're trying to raise as a specific issue here.

Azov are a part of the Ukrainian military. That's Ukraine's decision. If we give arms to Ukraine there's a good chance some of those arms will end up in the hands of Azov members.

There's not really any way to avoid that. We need to put diplomatic pressure on Ukraine to deal with the problem of far right extremists in their country (and, y'know, it would probably help if we were leading the way by doing more to deal with far right extremists in our own country), but abandoning them to the Russians just because they're not perfect paragons of progressive idealism isn't helping anything.