[![enter image description here](https://i.stack.imgur.com/g8dFK.png)](https://i.stack.imgur.com/g8dFK.png)

I have this structure in Firebase DB above 

**Case:** When a user sends a message to another user, newMessage field is updated -true- in customers/id/chats/chatid

Then what I am trying to do is fetching last message from messages/chatid
via the chatid I am getting from customers/id/chats/chatid

**Problem:** I do get the update and data on customers and sending notification but I need that last message, **Dont know how to do that**
No JavaScript experience at all. 
**Sample Chat id which I get on customers**
\_path: '/customers/m6QNo7w8X8PjnBzUv3EgQiTQUD12',
 \_data: 
 { chats: { '-**LCPNG9rLzAR5OSfrclG**': [Object] },

```js
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);

exports.sendNotif = functions.database.ref('/customers/{id}/chats/{id}/').onUpdate((event) => {

    const user = event.data.val();
    console.log('Event data: ', event.data);

    //HERE I WANT TO USE THAT CHAT ID TO FETCH MESSAGE in MESSAGES.
    // Get last message and send notification.
    // This works when newMessage field is updated.
    // However I neeed the message content from another table.

    var myoptions = {
      priority: "high",
      timeToLive: 60 * 60 * 24
    };

    // Notification data which supposed to be filled via last message. 
    const notifData = {
        "notification":
        {
          "body" : "Great Match!",
          "title" : "Portugal vs. Denmark",
          "sound": "default"
        } 
    }

  admin.messaging().sendToDevice(user.fcm.token, notifData, myoptions)
  .then(function(response) {
    console.log('Successfully sent message:', response);
  })
  .catch(function(error) {
    console.log('Error sending message:', error);
  });

    return ""
});
```