wp_insert_term does not wish to enter its knowledge into customized taxonomy

so I am engaged on a code to take knowledge from an array and put it in a customized taxonomy utilizing wp_insert_tem, however the knowledge will not go in. that is the json i wish to fetch, that is from a url

{
"genres": [
    {
      "name": "Military"
    },
    {
      "name": "Sci-fi"
    },
    {
      "name": "Shounen"
    }
  ],
}

that is the code i made

$end result = file_get_contents($url);
$array = json_decode($end result, true);
foreach($array['genres'] as $gen){
    wp_insert_term(
        $gen["name"],
        "genres",
        array(
            "description" => "",
            "slug" => sanitize_title($gen["name"]),
        ),
   );
}

please assist me