push notifications IOS using FCM - php

Question

I am using FCM to send push notification to IOS app, IOS dev provide me device token and SERVER_KEY, I search on google and tried different solutions but nothing worked for me , So let me know what is wrong with my code, Getting error {
"multicast_id": 8569689262516537799,
"success": 0,
"failure": 1,
"canonical_ids": 0,
"results": [
{
"error": "InvalidRegistration"
}
]
}
Thanks in advance
$ch = curl_init("https://fcm.googleapis.com/fcm/send");
//The device token.
$token = "c2420d68a0838d8fb6b26ef06278e899de73a149e93c9fe13df11f70f3dd5cc1"; //token here
//Title of the Notification.
$title = "Carbon";
//Body of the Notification.
$body = "Bear island knows no king but the king in the north, whose name is stark.";
//Creating the notification array.
$notification = array('title' => $title, 'text' => $body);
//This array contains, the token and the notification. The 'to' attribute stores the token.
$arrayToSend = array('to' => $token, 'notification' => $notification, 'priority' => 'high');
//Generating JSON encoded string form the above array.
$json = json_encode($arrayToSend);
//print_r($json); die();
//Setup headers:
$headers = array();
$headers[] = 'Content-Type: application/json';
$headers[] = 'Authorization: key=AAAAx6P1Nz0:APA91bEqkVCA9YRw9gpUvmF8UOVrYJ5T8672wfS_I7UAT3dA0g1QS7z-Z4fpn8JMiJ5kFRz9ZGc2K64hKZG-4__PAUqm733hqNDuFCDv9'; // key here
//Setup curl, add headers and post parameters.
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
//curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
//Send the request
$response = curl_exec($ch);
//Close request
print_r($response);
curl_close($ch);
//return $response;

Answer 1

token number ur sending is most probably wrong. try "/topics/all" this will send notification to all the users registered.