virtual [TOnlineAsyncOpHandle](API\Plugins\OnlineServicesInterface\Online\TOnlineAsyncOpHandle)< [FPromoteLobbyMember](API\Plugins\OnlineServicesInterface\Online\FPromoteLobbyMember) > PromoteLobbyMember ( [FPromoteLobbyMember::Params](API\Plugins\OnlineServicesInterface\Online\FPromoteLobbyMember\Params) && Params )