Just make an option to play 2 games (one with white and one with black) and add the points made in both games to decide who wins. If both players have the same amount of amount just call itt a draw.
(hide) If you want to play a game with an opponent of a similar level, you can define a required BKR range for a new game invitation. Then nobody with a BKR outside this range will be able to see/accept it. (Katechka) (show all tips)