public async void ConfigureSignalR()
        {
            // Client keys pair
            var client_x25519key = _dataEncryptor.CreateX25519EncryptorKey().Key;

            // Client public key bytes array
            var clientPublicKeyBytes = _dataEncryptor.GetX25519EncryptorPublicKeyBytes(client_x25519key);

            var token = GetToken(url);


            // SignalR hub url
            var stringUri = $"{url}/userNotification";



            var options = new HttpConnectionOptions()
            {
                AccessTokenProvider = () => Task.FromResult(token),
                Url = new System.Uri(stringUri),
            };

            var factory = new HttpConnectionFactory(Options.Create(options), new LoggerFactory());

            hubConnection = new HubConnection(factory, new JsonHubProtocol(), null);

            hubConnection.On <string>("PublicKeyExchange", keyDTOstring =>
            {
                // Server public key and nonce bytes
                var keyDto = JsonConvert.DeserializeObject <ServerPublicKeyDto>(keyDTOstring);

                ReadOnlySpan <byte> nonce = System.Convert.FromBase64String(keyDto.Nonce);

                // Create nonce from server nonce bytes
                clientEncryptorKey.Nonce = new NSec.Cryptography.Nonce(nonce.Slice(0, 4), nonce.Slice(4));

                clientEncryptorKey.Key = _dataEncryptor.CreateAes256GcmSymmetricKey(System.Convert.FromBase64String(keyDto.PublicKey), client_x25519key);
            });

            await hubConnection.StartAsync();

            await hubConnection.InvokeAsync("PublicKeyExchange", System.Convert.ToBase64String(clientPublicKeyBytes));
        }
        public async void ConfigureSignalR()
        {
            // Client keys pair
            var client_x25519key = _dataEncryptor.CreateX25519EncryptorKey().Key;

            // Client public key bytes array
            var clientPublicKeyBytes = _dataEncryptor.GetX25519EncryptorPublicKeyBytes(client_x25519key);

            // SignalR hub url
            var stringUri = $"{url}/userRegistration";

            var options = new HttpConnectionOptions()
            {
                Url = new System.Uri(stringUri),
            };

            var factory = new HttpConnectionFactory(Options.Create(options), new LoggerFactory());

            hubConnection = new HubConnection(factory, new JsonHubProtocol(), null);

            await hubConnection.StartAsync();
        }