CocoaMQTT(error): The deliver delegate is nil!!! the frame will be drop

I am trying to connect to MQTT broker, in very simple steps, but I am getting error CocoaMQTT(error): The deliver delegate is nil!!! the frame will be drop:PUBLISH(id: 2, topic: your-topic, payload: [72, 101, 108,...]

I have create one class as:

import CocoaMQTT

class MQTTManager: CocoaMQTTDelegate {
    var mqtt: CocoaMQTT!
    
    func mqtt(_ mqtt: CocoaMQTT, didPublishAck id: UInt16) {
      print("Published message with ID: \(id)")
    }
    
    func mqtt(_ mqtt: CocoaMQTT, didSubscribeTopics success: NSDictionary, failed: [String]) {  print("Subscribed to topics: \(success)") }
    
    func mqtt(_ mqtt: CocoaMQTT, didUnsubscribeTopics topics: [String]) { print("Unsubscribed from topics: \(topics)")  }
    
    func mqttDidPing(_ mqtt: CocoaMQTT) { print("Pinged!") }
    
    func mqttDidReceivePong(_ mqtt: CocoaMQTT) { print("Ponged!") }
    
    func mqttDidDisconnect(_ mqtt: CocoaMQTT, withError err: (any Error)?) { print("Disconnected from the MQTT")  }

    func mqtt(_ mqtt: CocoaMQTT, didConnectAck ack: CocoaMQTTConnAck) {
        if ack == .accept {
            print("Connected to the MQTT!")
        } else {
            print("Failed to connect to MQTT")
        }
    }

    func mqtt(_ mqtt: CocoaMQTT, didPublishMessage message: CocoaMQTTMessage, id: UInt16) {
        print("Data published successfully")
    }

    func mqtt(_ mqtt: CocoaMQTT, didReceiveMessage message: CocoaMQTTMessage, id: UInt16) {
        if let messageString = message.string {
            print("Received message on topic \(message.topic): \(messageString)")
        }
    }

    func connectMQTT() {
        mqtt = CocoaMQTT.init(clientID: "your-client-id-435345", host: "your-client-id-435345", port: 1883)
        //tried with CocoaMQTT(clientID: "your-client-id-435345", host: "your-client-id-435345", port: 1883)
        mqtt.delegate = self
        mqtt.connect()
    }
    func subscribeToTopic(topic: String) {
        mqtt.subscribe(topic)
    }
    func publishData(topic: String, message: String) {
        mqtt.publish(topic, withString: message, qos: .qos1)
    }
}

I am trying to use it in function as:

    func sendTelemetryMsg(password: String, url: String, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) -> Void {
        
    let mqttManager = MQTTManager();
     mqttManager.connectMQTT()

        // Subscribe to a topic
        let topic = "your-topic"
        mqttManager.subscribeToTopic(topic: topic)

        // Publish data to the IoT device
        let message = "Hello, IoT Device!"
        mqttManager.publishData(topic: topic, message: message)
    }