7 pace tracker is not responsing properly - Getting an error while saving the time tracker

An unexpected error occurred invoking 'StartTracking' on the server. Exception: ExecuteAction failed  at method: GetWorkItemsByIds
Message:  at method: RequestData
Message: Your user or Service Account user does not have enough permissions to perform calls to DevOps API. Please check permissions.

StackTrace:
   at Timetracker.JointCodebase.BusinessLayer.Providers.Implementation.VisualStudioProvider.RequestData[T](VisualStudioRequest request, Method method, Action`1 preRequestExecution, String contentType) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\Providers\Implementation\VisualStudioProvider.cs:line 1134
   at Timetracker.VSTS.BusinessLayer.Providers.VSTSVisualStudioProvider.RequestData[T](VisualStudioRequest request, Method method, Action`1 preRequestExecution, String contentType) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.VSTS.BusinessLayer\Providers\VSTSVisualStudioProvider.cs:line 109
   at Timetracker.JointCodebase.BusinessLayer.Providers.Implementation.VisualStudioProvider.ExecuteGenericRequest[T](VsoTokenModel tokenModel, String url, Method method, String query) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\Providers\Implementation\VisualStudioProvider.cs:line 1086
   at Timetracker.JointCodebase.BusinessLayer.Providers.Implementation.VisualStudioProvider.<>c__DisplayClass38_1.<GetWorkItemsByIds>b__1() in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\Providers\Implementation\VisualStudioProvider.cs:line 353
   at System.Threading.Tasks.Task.InnerInvoke()
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)

StackTrace:
   at Timetracker.JointCodebase.BusinessLayer.Providers.Implementation.VisualStudioProvider.GetWorkItemsByIds(Project virtualProject, VsoTokenModel tokenModel, Int32[] tfsIds, String[] fields) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\Providers\Implementation\VisualStudioProvider.cs:line 392
   at Timetracker.JointCodebase.BusinessLayer.CachingWebAppServices.WorkItemsProvider.GetWorkItems(VsoTokenModel vsoToken, Project project, IList`1 ids, IList`1 fields, WorkItemsStorageSourcePriority itemsStorageSourcePriority) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\CachingWebAppServices\WorkItemsProvider.cs:line 257
   at Timetracker.JointCodebase.BusinessLayer.Context.Services.ContextWorkItemsService.GetWorkItemsFromDevOps(Int32[] itemIds, VsoTokenModel tokenModel, String[] fields, Boolean expand, Project project) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\Context\Services\ContextWorkItemsService.cs:line 727
   at Timetracker.JointCodebase.BusinessLayer.Context.Services.ContextWorkItemsService.UpdateWorkItemsFieldsBatch(IEnumerable`1 items, Nullable`1 projectId, VsoTokenModel tokenModel) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\Context\Services\ContextWorkItemsService.cs:line 0
   at Timetracker.ServerSideTrackingBusinessLogic.Logic.Shared.WorkLogSyncService.DoUpdateTfsFields(IList`1 tracks) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.ServerSideTrackingBusinessLogic\Logic\Shared\WorkLogSyncService.cs:line 234
   at Timetracker.ServerSideTrackingBusinessLogic.Logic.ClientApi.ClientApiService.StopAction(TrackingUser trackingUser, StopReason reason) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.ServerSideTrackingBusinessLogic\Logic\ClientApi\ClientApiService.cs:line 510
   at Timetracker.ServerSideTrackingBusinessLogic.Logic.ClientApi.ClientApiService.StartTracking(Nullable`1 tfsId, String remark, Int32 timeZoneOffset, Nullable`1 activityType, Nullable`1 isBillable) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.ServerSideTrackingBusinessLogic\Logic\ClientApi\ClientApiService.cs:line 195
   at Timetracker.ServerSideTrackingBusinessLogic.Logic.Hubs.v3._2.TrackingHub.<>c__DisplayClass4_0.<StartTracking>b__0(IClientApi api) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.ServerSideTrackingBusinessLogic\Logic\Hubs\v3.2\TrackingHub.cs:line 36
   at Timetracker.ServerSideTrackingBusinessLogic.Logic.Hubs.BaseHub`1.ExecuteAction[TOut](Func`2 func) in C:\a\2\s\TimetrackerOnline\TimetrackerOnline.ServerSideTrackingBusinessLogic\Logic\Hubs\BaseHub.cs:line 120