[TOnlineAsyncOpHandle](API\Plugins\OnlineServicesInterface\Online\TOnlineAsyncOpHandle)< [FRejectSessionInvite](API\Plugins\OnlineServicesInterface\Online\FRejectSessionInvite) > RejectSessionInvite ( [FRejectSessionInvite::Params](API\Plugins\OnlineServicesInterface\Online\FRejectSessionInvite\Params) && Params )