Call a PHP Function with Multiple Parameters that is outside the AJAX Handler

Sorry for late reply. First allow POSTing from your WordPress to your game server (using Apache or PHP or whatever method).

Then on your AJAX handler function, use wp_remote_post to POST your data to the Game Server.

$request = wp_remote_post( 'https://urltoyour/gameserver/voting/endpoint', array(
    'body'        => $body, // array/json formatted voting data

) );

$response = wp_remote_retrieve_body( $request );

For more in depth information, please check WordPress HTTP API.