In order to complain about the player, after finishing the game, go to the main screen of the game and in the upper left corner we see the "!" in a triangle, press it.
Also in the description it is worthwhile to clearly and clearly describe the situation. It is best to indicate the time in the match when there was a violation.
The clearer and clearer you express your thoughts, the faster your application will be considered and the player will be punished.
If for some reason you cannot complain through the functionality described above, you can always do it after the end of the game. If t