Is that possible that I can ban the player from sending statistic via GameManager?
Is that possible that I can ban the player from sending statistic via GameManager?
The Client API call for updating player statistics is turned off by default, so players can only write statistics to the service from the client if you specifically allow that (which we recommend against). We do provide banning of accounts, which we would also recommend using for any user who is being abusive or otherwise disruptive to your title. But if the question is, can you block only specific users from updating statistics while allowing others to, then I'm afraid the answer is no, we don't provide specific-user-targeted enabling/disabling of API calls.
What the other method that I can use to send player's score without sending from client?
You can use the Server version of UpdatePlayerStatistics from Cloud Script. That gives you a server-authoritative way to do some basic checks on what the client is saying it did, and add cheat checks both pre-launch and then over time, as you identify ways people are attempting to abuse the game.
