init method
Initialize and sign in to TUICallEngine.
Params:
sdkAppID: TUICall/TUIKit application ID from Tencent Cloud console.userId: Unique user identifier.userSig: Auth signature corresponding touserId.
Returns: TUIActionCallback indicating success or failure.
Implementation
@override
Future<TUIActionCallback> init(int sdkAppID, String userId, String userSig) async {
return _callEngineNative.initCallEngine(sdkAppID, userId, userSig);
}