推送通知未从PHP API发送

Question

我已经用PHP编写了一个API，该API将接收Firebase令牌，并将推送通知发送到Android设备。

我已经测试了Android辅助代码，它使用令牌从Firebase控制台接收示例通知。但是，当我尝试从PHP api发送邮件时，它没有发送通知。

这是我的PHP API。

// send firebase push notifcaiton
            $url = 'https://fcm.googleapis.com/fcm/send';
                $api_key = 'xxxxxxxxxxxxxxxxxxxxxxxxx';

                $fields = array (
                    'registration_ids' => array (
                    $pnsToken
                ),
                    'data' => array (
                        "message" => $message,
                        "guestId" => $guestId,
                        "guestEntryId" => $guestEntryId,
                        "guestName" => $guestName,
                        "guestAddress" => $guestAddress,
                        "reason" => $reason
                    )
                );

            //header includes Content type and api key
            $headers = array(
                'Content-Type:application/json',
                'Authorization:key='.$api_key
            );

            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
            $result = curl_exec($ch);
            if ($result === FALSE) {
                die('FCM Send Error: ' . curl_error($ch));
            }
            curl_close($ch);

我不知道为什么它没有从PHP api发送推送通知。

编辑

这是我收到的fcm错误：

"fcmResult": "{\"multicast_id\":7084003691931660410,\"success\":0,\"failure\":1,\"canonical_ids\":0,\"results\":[{\"error\":\"NotRegistered\"}]}",