fetall error

[ghost]

Hello guys . I want to have a route on my google map app and I use this code -> `
//ROUTE

// Pass your source and destination coordinates in this method.
func getPolylineRoute(from source: CLLocationCoordinate2D, to destination: CLLocationCoordinate2D){

    let config = URLSessionConfiguration.default
    let session = URLSession(configuration: config)

    let url = URL(string: "http://maps.googleapis.com/maps/api/directions/json?origin=\(source.latitude),\(source.longitude)&destination=\(destination.latitude),\(destination.longitude)&sensor=false&mode=driving&key=**MY KEY**")!

    let task = session.dataTask(with: url, completionHandler: {
        (data, response, error) in
        if error != nil {
            print(error!.localizedDescription)
        }else{
            do {
                if let json : [String:Any] = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any]{

                    let routes = json["routes"] as? [Any]
                    let overViewPolyLine = routes?[0] as?[String:Any]
                    let polyString = overViewPolyLine?["points"] as?String

                    //Call this method to draw path on map
                    self.showPath(polyStr: polyString!)
                }

            }catch{
                print("error in JSONSerialization")
            }
        }
    })
    task.resume()
}

func showPath(polyStr :String){
    let path = GMSPath(fromEncodedPath: polyStr)
    let polyline = GMSPolyline(path: path)
    polyline.strokeWidth = 3.0
    polyline.map = googleMapsView // Your map view
}

.` I have a crush on this line of my codes , I don't know what should I do . Any answer would be appreciated ☺️