I open many connections in my API and stay open and I need to close each of those connections

<?php
    $mng = new MongoDB\Driver\Manager("mongodb://localhost:27017");
    $condition = ['shape'=>['$nearSphere'=>[
        '$geometry'=>[
        'type'=>'Point',
        'coordinates'=>[-98.280735, 19.063866]],'$maxDistance'=>500]]]; 
    $option=[];
    $query = new MongoDB\Driver\Query($condition,$option);  
    $cursor = $mng->executeQuery("geom.polygons", $query);
    foreach($cursor as $document) {
        echo "$document->name<br>";
    }
?>