[2021] Where can we go to report cheaters with evidence?

As guys above said - best way is to use server replay functionalit.

Launch the game - alt tab to site, search for the replay of match you think of.

Launch it on site - you will get request to switch back to the game - do it.

Now you will see battle from server perspective (so no lags from your client, point of view from every player on map etc).

This is the way to actually check how other players play the battle - you can see what the saw, what they heard etc.

If you still suspect that someone was using 3rd party app and break rules - report him via that replay. Best to add time stamps of the situation.

And please, do not accuse someone for cheating ion public. Majority of such cases are false accusations, because you saw battlefield from your limited perspective, not from perspective of your enemy.

Cheers!