Use the in-game (or on-profile) report button and make sure to include the game link. If this is one player with two accounts, the admins have the tools to pick up on that. Keep in mind that ordinary collusion is not
against the rules:
Players working together is not against the rules, and you should not report players for doing so. To avoid collusion, play in 1 v 1 games where collusion is impossible, or in team games (since then the collusion is pre-arranged), or just play with friends you trust. You may also wish to blocklist this player so you don't have to play with them anymore.
Edited 8/13/2020 04:09:18