Need help with setting values via terminal command and via API

RouterOS Beginner Basics
1

hello I’m trying to set my wall-gardened ip list values via API and in Terminal inside routerOS, my problem is how can i set values to null, in some field its working but how can i set it from a value to null when i don’t need the parameter

via terminal
/ip hotspot walled-garden ip set numbers=14 action=accept  dst-address=""

via api
$api->comm('/ip/hotspot/walled-garden/ip/set', array(
                '.id'=>"*1A",
                'action' => "reject",
                'server'=>""
            ));
2

never mind silly me should have been using Set and Unset