How to launch Watch app from the companion iOS app?

I wanted to launch the watch app from companion app. I have used the WCSession delegate method. Also setup the Receive message and Receive data delegate in the iOS app. Still it is not doing anything.

What is the process to launch the Watch App from Companion app?

let data = ["name": "ABC", "age": 18] as [String : Any];
WCSession.default.sendMessageData(theJSONData) { (info) in
        print("Message sent as : data \(info)")
      } errorHandler: { (Error) in
        print("Error : \(Error)")
      }

func session( session: WCSession, didReceiveMessage message: [String : Any]) {
  }
   
  func session( session: WCSession, didReceiveMessageData messageData: Data) {
  }