Creating a global variable using API

RouterOS Scripting
1

I need to create a global variable with name user10 and value 4000 but i can find the way to doit:

   $API = new RouterosAPI();
    if ($API->connect($server['ip'], $usuario, $clave)) {
        $API->comm("/global", [
            "name" => $name,
            "value" => $uniqueFileName,
        ]);

try this way but dont work, any ideas?