single_device_push_notification.go

response, err := fcmClient.Send(context.Background(), &messaging.Message{
  
  Notification: &messaging.Notification{
    Title: "Congratulations!!",
    Body: "You have just implement push notification",
  },
    Token: "sample-device-token", // it's a single device token
})

if err != nil {
     return err
}