Export To file in group receiving needs effective identity error

I am currently trying to run the export to file in group rest api however I am getting the "needs effective identity" even though I am providing that.  Can someone point to me as to what I am doing wrong?

https://learn.microsoft.com/en-us/rest/api/power-bi/reports/export-to-file-in-group#code-try-0

        public string  PBIInitialExportRequest(int customerID, Guid workspaceGUID, Guid datasetGUID, Guid reportGUID, string format)  
        {
            try
            {
                //string baseUrl = $"{ConfigurationDataAccess.PBIConfigs.RestApiGroupUrl}/{ds.WorkspaceGUID}/datasets/{ds.DatasetGUID}/Default.BindToGateway";
                string baseUrl = $"{ConfigurationDataAccess.PBIConfigs.RestApiGroupUrl}/{workspaceGUID}/reports/{reportGUID}/ExportTo";
                //POST https://api.powerbi.com/v1.0/myorg/groups/{groupId}/reports/{reportId}/ExportTo
                RestClient client = new RestClient(baseUrl);
                RestRequest request = CreatePostRestRequest();

                Guid gatewayObjectID = new Guid(ConfigurationDataAccess.PBIConfigs.AzureDatabricksGatewayObjectId);

                List<Guid> datasourceObjectIds = new List<Guid> { new Guid(ConfigurationDataAccess.PBIConfigs.AzureDatabricksDataSourceObjectId) };

                request.AddJsonBody(new
                {
                    Format = format,
                    EffectiveIdentity = new
                    {
                        Username = customerID.ToString(),
                        Roles = new List<string> { "Company_User" },
                        Datasets = new List<string> { datasetGUID.ToString() }
                    },
                    datasourceObjectIds = datasourceObjectIds,
                    gatewayObjectID = gatewayObjectID
                });

                IRestResponse response = client.Execute(request);
            

                if (response.IsSuccessful)
                {
                    // Parse the response content to extract the id
                    var jsonResponse = JObject.Parse(response.Content);
                    string exportID = jsonResponse["id"].ToString();

                    //ApplicationLog.LogMessage($"Gateway assigned to dataset ({ds.DatasetName}) successfully. Export ID: {id}", LogName);
                    return exportID;
                }
                else
                {
                    // The request failed
                    //ApplicationLog.LogMessage($"Failed to assign gateway to dataset ({ds.DatasetName}): {response.StatusCode}", LogName); ;
                    return null;
                }
            }
            catch (Exception er)
            {
                return null;
            }
        }