Variable: private IRestRequest _restRequest;
-------------------------------------
Constructor: 

public RefinitivRepository(IOptions<RefinitivDSSConfiguration> refinitivConfig, IRestClient restClient, IRestRequest restRequest, IOptions<AzureStorageConfiguration> storageConfig, IMemoryCache cache, ILogger<RefinitivRepository> logger)
        {
            _refinitivConfig = refinitivConfig;
            _restClient = restClient; 
            _storageConfig = storageConfig;
            _cache = cache;
            _logger = logger;

            restRequest.AddHeader("Prefer", "respond-async, wait=120");
            restRequest.AddHeader("Content-Type", "application/json");
            restRequest.Timeout = 300000;
            _restRequest = restRequest;

            fieldNames = new string[] { "Base Currency Code", "Universal Close Price", "Trade Date"};

            dailyJobFieldNames = new string[] { "Trade Date", "Base Currency Code", "Currency Code", "Universal Close Price", "FXIR Scaling Factor" };

        }

------------------------------------------
 public async Task<IRestResponse> GetInstrumentListExchangeRates(string authToken)
        {
            _logger.LogInformation("Start of GetInstrumentListExchangeRates in RefinitivRepository");
            IRestResponse instrumentListResponse = null;
            try
            {
                string restRequest = PrepareDSSDailyJobCurrencyExchangeRequest(authToken);

                Parameter dailyJobParameter = new Parameter("FxDailyJobParameter", restRequest, ParameterType.RequestBody);

                _restRequest.AddParameter(dailyJobParameter);

                instrumentListResponse = await _restClient.ExecutePostTaskAsync(_restRequest);

                if (instrumentListResponse != null && !string.IsNullOrWhiteSpace(instrumentListResponse.Content) && instrumentListResponse.StatusCode == HttpStatusCode.OK)
                {
                    _logger.LogInformation("RefinitivRepository-GetInstrumentListExchangeRates: DSS response received in the initial request");
                    return instrumentListResponse;
                }
                else if (instrumentListResponse != null && instrumentListResponse.Headers != null && instrumentListResponse.Headers.Count > 0)
                {
                    object locationHeaderValue = instrumentListResponse.Headers.FirstOrDefault(h => h.Name == "Location")?.Value;
                    _logger.LogInformation("RefinitivRepository-GetInstrumentListExchangeRates: Use locationheadervalue to get DSS response and the header value is: " + locationHeaderValue.ToString());
                    if (locationHeaderValue != null)
                    {
                        _logger.LogInformation("RefinitivRepository-GetInstrumentListExchangeRates: Start of calling GetDailyJobExtractionResponse");
                        instrumentListResponse = await GetDailyJobExtractionResponse(locationHeaderValue.ToString(), authToken);
                    }
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error occured in GetInstrumentListExchangeRates in RefinitivRepository");
                throw ex;
            }
            _logger.LogInformation("End of GetInstrumentListExchangeRates in RefinitivRepository");
            return instrumentListResponse;
        }
------------------------------------------------

private string PrepareDSSDailyJobCurrencyExchangeRequest(string authToken)
        {
            string dailyJobExchangeRequest = string.Empty;
            try
            {
                _restRequest.Parameters.RemoveAll(R => R.Name == "Authorization" || R.Name == "AuthenticationParameter"
                                         || R.Name == "EODParameter" || R.Name == "SingleDayParameter"
                                         || R.Name == "MonthParameter" || R.Name == "YearParameter" || R.Name == "MultiCurrencyParameter" || R.Name == "FxDailyJobParameter");

                _restRequest.AddHeader("Authorization", $"Token {authToken}");
                _restClient.BaseUrl = new Uri($"{_refinitivConfig.Value.ServiceUrl}Extractions/ExtractWithNotes");


                Identifier identifier = new Identifier();
                identifier.OdataType = "#ThomsonReuters.Dss.Api.Extractions.ExtractionRequests.InstrumentListIdentifierList";
                identifier.InstrumentListId = _refinitivConfig.Value.InstrumentListId;

                DSSDailyJobCurrencyExchangeRequest dailyJobRequest = new DSSDailyJobCurrencyExchangeRequest
                {
                    ExtractionRequest = new ExtractRequest
                    {
                        OdataType = "#ThomsonReuters.Dss.Api.Extractions.ExtractionRequests.EndOfDayPricingExtractionRequest",
                        Condition = null,
                        ContentFieldNames = dailyJobFieldNames.ToList<string>(),
                        IdentifierList = identifier
                    }
                };
                dailyJobExchangeRequest = JsonSerializer.Serialize<DSSDailyJobCurrencyExchangeRequest>(dailyJobRequest);

            }
            catch (Exception ex)
            {
                throw ex;
            }
            return dailyJobExchangeRequest;
        }
----------------------------------------------------------

private async Task<IRestResponse> GetDailyJobExtractionResponse(string baseUrl, string authToken)
        {
            _logger.LogInformation("Start of GetDailyJobExtractionResponse in RefinitivRepository");
            IRestResponse restResponse;
            try
            {
                _restRequest.Parameters.RemoveAll(R => R.Name == "Authorization" || R.Name == "AuthenticationParameter"
                                        || R.Name == "EODParameter" || R.Name == "SingleDayParameter"
                                        || R.Name == "MonthParameter" || R.Name == "YearParameter" || R.Name == "MultiCurrencyParameter" || R.Name == "FxDailyJobParameter");

                _restRequest.AddHeader("Authorization", $"Token {authToken}");
                _restClient.BaseUrl = new Uri(baseUrl);

                restResponse = await _restClient.ExecuteGetTaskAsync(_restRequest);

            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error occured in GetDailyJobExtractionResponse in RefinitivRepository");
                throw ex;
            }
            _logger.LogInformation("End of GetDailyJobExtractionResponse in RefinitivRepository");
            return restResponse;
        }
--------------------------------------