foreach ($s as $key => $v) {
    $numbers[] = "'".$v['telefon']."'";
}

$n = implode(',', $numbers);


$curl = curl_init();
$params = [
    'api_id' => 'XXXXXXXXXXXXXXXXXXXX',
    'api_key' => 'XXXXXXXXXXXXXXXXXX',
    'sender' => 'XXXXXXXX',
    'message_type' => 'turkce',
    'message' => '12445aaxzxcz121523534124asd1 Yeni123 hizasdasdmet talebi geldi hemen teklif vermek için islerburada.com. Uygulama: https://bit.ly/3KpFHrB',
    'phones' => [
        $n
    ]
];
$curl_options = [
    CURLOPT_URL => 'https://api.vatansms.net/api/v1/1toN',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT => 0,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_SSL_VERIFYPEER => 0,
    CURLOPT_POSTFIELDS => json_encode($params),
    CURLOPT_HTTPHEADER => [
        'Content-Type: application/json'
    ]
];
curl_setopt_array($curl, $curl_options);
$response = curl_exec($curl);
$data = json_decode($response, true);
curl_close($curl);

echo '<br>'.$response;