Delegate and DataSource not woking in MessageKit Swift IOS

I'm using the MessageKit for chating when I calling the its delegate and datasource it saying (Cannot find 'messagesCollectionView' in scope) please see the code and guide me thanks.

import UIKit
import FirebaseAuth
import MessageKit

struct Message: MessageType{
    var sender: SenderType
    var messageId: String
    var sentDate: Date
    var kind: MessageKind
}

struct sender: SenderType{
    var photo: String
    var senderId: String
    var displayName: String
}
class ChatDashboard: UIViewController {

    @IBOutlet weak var lblUser: UILabel!
    
    var userActive: String? = nil
    
    
    override func viewDidLoad() {
        super.viewDidLoad()

         messagesCollectionView.messagesDataSource = self
         messagesCollectionView.messagesLayoutDelegate = self
         messagesCollectionView.messagesDisplayDelegate = self //not working delegate and datasource
        if let userData = userActive{
            self.lblUser.text = userData
        }
        
    }
    
    override func viewDidAppear(_ animated: Bool) {
    }

}

Have a look at their example project usage. Should clear out lots of confusion.

Link: https://github.com/MessageKit/MessageKit/tree/master/Example

As for your query,

Can't find messagesCollectionView because MessagesViewControllerneeds to be extended to access that.