How to put the file download progress on the label on the MacOS App interface using Swift?

Question

I write a download button that works fine, but can't show the percentage progress on the label.

I tried putting the label in the FileDownloader class, but it's not updating and showing on the interface.

0.041681744
0.045944795
0.11841663
0.12694274
0.13546883
.
.
.
99.66489
99.84393
99.84819
100.0

this is my code:

class ramdisk: NSViewController {
...
class FileDownloader : NSObject, URLSessionDownloadDelegate {
        var url : URL?
        // will be used to do whatever is needed once download is complete
        var yourOwnObject : NSObject?

        init(_ yourOwnObject : NSObject)
        {
            self.yourOwnObject = yourOwnObject
        }

        //is called once the download is complete
        func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL)
        {
            //copy downloaded data to your documents directory with same names as source file
            let documentsUrl =  FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
            //FileManager.default.
            let destinationUrl = documentsUrl!.appendingPathComponent(url!.lastPathComponent)
            let dataFromURL = NSData(contentsOf: location)
            dataFromURL?.write(to: destinationUrl, atomically: true)
            //now it is time to do what is needed to be done after the download
            //yourOwnObject!.callWhatIsNeeded()
        }

        //this is to track progress
        func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) {
                let progress = Float(totalBytesWritten) / Float(totalBytesExpectedToWrite)
                let progressPercentage = progress * 100
                print(progressPercentage)
            }

        // if there is an error during download this will be called
        func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?)
        {
            if (error != nil)
            {
                //handle the error
                print("Download completed with error: \(error!.localizedDescription)");
            }
        }

        //method to be called to download
        func download(url: URL)
        {
            self.url = url
            //download identifier can be customized. I used the "ulr.absoluteString"
            let sessionConfig = URLSessionConfiguration.background(withIdentifier: url.absoluteString)
            let session = Foundation.URLSession(configuration: sessionConfig, delegate: self, delegateQueue: nil)
            let task = session.downloadTask(with: url)
            task.resume()
        }

    }
    
    @IBAction func downloads(_ sender: Any) {
        let strURL = "http://downloads.xyz/test.zip"
        let url = URL(string: strURL)
        FileDownloader(url! as NSObject).download(url: url!)
    }
...
}

I write a download button that works fine, but can't show the percentage progress on the label.

I tried putting the label in the FileDownloader class, but it's not updating and showing on the interface.