funcion de Arduino IDE que manda un mqtt por SIM7080G requeire el topic y el mensaje

void sendmqtt(str topic ,str msg)
{
    Serial.println(String("AT+NSOST=0,\"mqtt.thingspeak.com\",1883,")+String(topic.length())+String(",")+String(msg.length())+String(",")+topic+msg);
    Serial.println("AT+NSOST=0,\"mqtt.thingspeak.com\",1883,4,4,\"1\"");
    Serial.println();
}