Conference Call Not working

[Rabi-tech]

in my app one to one call working fine. but when i have to try make a conference call i am getting some problem... when i try to add another person on running call it is not working to make bridge the between them.
i have used this codes. please look at the code and help me out.

func conferenceButtonAction(_ sender: Any) {
self.callManager.startCall(toNumber: number, for: account! ) { (call, error) in
if error != nil {
DDLogWrapper.logError("Could not start call")
self.callButton.isEnabled = true
} else {
self.call = call
self.callManager.add(self.call!)
self.callManager.calls(for: account)
DispatchQueue.main.async {
//self.performSegue(withIdentifier: "toCall", sender: self)
self.navigationController?.popViewController(animated: false)
}
}
}
}

[fukemy]

i called start call but get any observer , did u solved this?