How can I setup SIP_UA in Flutter

I am trying to build a softphone application and I am having a hard time implementing sip_ua and make calls. There's not a lot of resource online about this specific library. This is the state of the code at the moment.

I tried making a call with this functionality and it doesn't seem to be making a call. No errors, no returns.

final UaSettings uaSettings = UaSettings()
 ..webSocketUrl = "wss://ip:8089/ws"
 ..password = ""
 ..userAgent = ""
 ..transportType = TransportType.WS
 ..webSocketSettings.allowBadCertificate = true
 ..uri = "username@ip"
 ..displayName = "displayName";
await _sipuaHelper.start(uaSettings);


final Map<String, dynamic> mediaConstraints = <String, dynamic>{
 "video": true,
 "audio": true,
};
final MediaStream mediaStream = 
  await navigator.mediaDevices.getUserMedia(mediaConstraints);
await sipuaHelper.call(target, mediaStream: mediaStream);