I want to do a download that can continue in the background in swift, but when I switch to the background, the bluetooth file transfer stops

Question

func applicationDidEnterBackground(_ application: UIApplication) {
    print("Entered Background")

    bgTask = application.beginBackgroundTask(expirationHandler: {
        self.bgTask = UIBackgroundTaskIdentifier.invalid
        self.cb_central = CBCentralManager()
        self.cb_central.delegate = self
        
        self.centralManagerDidUpdateState(self.cb_central)
        Definations.isFileTransferInProgress = true
        VoiceRecordMainVC().downloadFile()
    })
   
}

func applicationWillEnterForeground(_ application: UIApplication) {
    UIApplication.shared.endBackgroundTask(bgTask)
}

I have such a code and when it goes to the background, I tell the download to continue, actually I am telling it to start the download again. Do you think it is possible to do this and how can I do it, thank you for your help.