Footage released by Russian sources shows Ukrainian ATGM positions located on the top of apartment buildings being slammed with indirect fires.

It's unclear exactly when or where this footage was filmed. That said, towards the beginning of the invasion of Ukraine there were a lot of reports from Russian forces that the indirect fires on civilian homes were required due to them becoming legitimate military threats to their troops. This footage, which was probably recorded somewhere around the beginning of the conflict, shows legitimate military targets located on the rooftop of civilian apartments.

Due to the nature of warfare, when the Ukrainian military put those ATGM systems on the roof and stationed their ATGM teams there, they did in fact make those apartments legitimate military targets. This is not an opinion, it's a simple fact.