'fcm' => [
    'priority' => 'normal',
    'dry_run' => false,
    'apiKey' => 'My-Api-key',
],

if(count($fcmDeviceIds) > 0) {
    $this->sendFCM($fcmDeviceIds, $payload, $addedPost);
  }

private function sendFCM($tokens, $payload, $addedPost) {

    $poroductDetail = Product::find($addedPost->product_id)->first();
    $productTitle   = $poroductDetail->title;
    $payloadData    = ([$addedPost, 'notificationType' => 'postNotification']);

    try {
        $push = new PushNotification('fcm');
        $feedback = $push->setMessage([
            'fcm' => [
                'alert' => [
                    'title' => isset($payload['title']) ? $payload['title'] : 'myTitle',
                    'body' => $payload['body']." for ".$productTitle
                ],
                'sound' => isset($payload['sound']) ? $payload['sound'] : 'default'

            ],
            'extraPayLoad' => $payloadData
        ])->setDevicesToken($tokens)->send()->getFeedback();

    } catch (Exception $ex) {
        Log::error($ex->getTraceAsString());
    }
}