How to add item to MIGX programmatically

<?php

$newitem['image'] = 'test.jpg';
$newitem['title'] = 'myTitle';


if ($resource = $modx->getObject('modResource', $resourceID)) {
    $oldvalue = $resource->getTvValue($tvname);
    $items = $modx->fromJson($oldvalue);

    if ($tv = $modx->getObject('modTemplateVar', array('name' => $tvname))) {
        
        $items[] = $newitem; 
        $tv->setValue($resourceID, $modx->toJson($items));
        $tv->save();
    }
}