Error: NameResolutionFailure

  at System.Net.WebConnection.Connect (System.Net.WebOperation operation, System.Threading.CancellationToken cancellationToken) [0x00044] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.WebConnection.InitConnection (System.Net.WebOperation operation, System.Threading.CancellationToken cancellationToken) [0x000cc] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.WebOperation.Run () [0x0009a] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.WebCompletionSource`1[T].WaitForCompletion () [0x00094] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.HttpWebRequest.RunWithTimeoutWorker[T] (System.Threading.Tasks.Task`1[TResult] workerTask, System.Int32 timeout, System.Action abort, System.Func`1[TResult] aborted, System.Threading.CancellationTokenSource cts) [0x000f8] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.HttpWebRequest.GetResponse () [0x00016] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.WebClient.GetWebResponse (System.Net.WebRequest request) [0x00000] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.WebClient.DownloadBits (System.Net.WebRequest request, System.IO.Stream writeStream) [0x000e6] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.WebClient.DownloadDataInternal (System.Uri address, System.Net.WebRequest& request) [0x00061] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at System.Net.WebClient.DownloadData (System.Uri address) [0x00011] in <4e15bbae9d7043d8afd6cfd50bd9bd5a>:0
  at (wrapper remoting-invoke-with-check) System.Net.WebClient.DownloadData(System.Uri)
  at TL.Lib.TwoFactorAuth.Providers.Qr.BaseHttpQrCodeProvider.DownloadData (System.Uri address) [0x00034] in <c44836e4f7054286b3c548c9498d34cd>:0
  at TL.Lib.TwoFactorAuth.Providers.Qr.QRicketQrCodeProvider.GetQrCodeImage (System.String text, System.Int32 size) [0x0000a] in <c44836e4f7054286b3c548c9498d34cd>:0
  at TL.Lib.TwoFactorAuth.TwoFactorAuth.GetQrCodeImageAsDataUri (System.String label, System.String secret, System.Int32 size) [0x00036] in <c44836e4f7054286b3c548c9498d34cd>:0
  at TL.Lib.TwoFactorAuth.TwoFactorAuth.GetQrCodeImageAsDataUri (System.String label, System.String secret) [0x00001] in <c44836e4f7054286b3c548c9498d34cd>:0
  at TL.Lib.Utils.GetQrCodeImageAsDataUri (System.String secret) [0x000a0] in <c44836e4f7054286b3c548c9498d34cd>:0
  at TL.API.AppEP.TFAGet () [0x00046] in <c44836e4f7054286b3c548c9498d34cd>:0
  at (wrapper managed-to-native) System.Reflection.RuntimeMethodInfo.InternalInvoke(System.Reflection.RuntimeMethodInfo,object,object[],System.Exception&)
  at System.Reflection.RuntimeMethodInfo.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x0006a] in <a17fa1457c5d44f2885ac746c1764ea5>:0

Your problem may be related to the topic in this link https://tinycp.com/community/show/672#sidebar. It may be giving this error because the system does not see your subscription. Because I have the same problem as you, and when I browse other pages, I get the subscription error and the same error as you, even though my account on the tinycp official site has a subscription and I have time.