Get 404 Resource Not Found error when trying to download

1. I created a function app in azure portal for the callback to download docs. 2. And then I created some transactions through the Dashboard. 3. Then I got emails said eSignLive Callback failed. Failed to communicate with the callback server. URL: https://esigndemo.azurewebsites.net/api/home Payload: {"@class":"com.silanis.esl.packages.event.ESLProcessEvent","name":"DOCUMENT_SIGNED","sessionUser":"86162f59-6672-448c-8bb0-a24caf4b5343","packageId":"2zfJNghK7kbSVSip_Ja5JXQ0XgE=","message":null,"documentId":"122ac59cc233bb66098d6f89266047578865af0d6317946e","createdDate":"2019-04-24T02:37:28.160Z"} Reason(s): 500: Internal Server Error 4. Next, I used postman to test my dotnet core web MVC, every time it went to byte[] content = eslClient.DownloadZippedDocuments(pkgId); it showed exception {"messageKey":"error.validation.packageDoesNotExist","technical":"Could not retrieve the transaction summary for transaction uid: 2zfJNghK7kbSVSip_Ja5JXQ0XgE=","message":"The specified package does not exist.","code":404,"name":"Resource Not Found"} `string packageId = jsonBody["packageId"].ToString(); PackageId pkgId = new PackageId(packageId); byte[] content = eslClient.DownloadZippedDocuments(pkgId); ` Silanis.ESL.SDK.EslServerException HResult=0x80131500 Message=Could not download the documents to a zip file. Exception: The remote server returned an error: (404) Not Found. HTTP GET on URI https://sandbox.e-signlive.ca/api/packages/2zfJNghK7kbSVSip_Ja5JXQ0XgE=/documents/zip. Optional details: {"messageKey":"error.validation.packageDoesNotExist","technical":"Could not retrieve the transaction summary for transaction uid: 2zfJNghK7kbSVSip_Ja5JXQ0XgE=","message":"The specified package does not exist.","code":404,"name":"Resource Not Found"} Source=Silanis.ESL StackTrace: at Silanis.ESL.SDK.Services.PackageService.DownloadZippedDocuments(PackageId packageId) at eSignDemo.Controllers.HomeController.Listener() in C:\Users\xxie\Projects\eSignDemo\eSignDemo\Controllers\HomeController.cs:line 37 at Microsoft.Extensions.Internal.ObjectMethodExecutor.Execute(Object target, Object[] parameters) at Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.SyncActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments) at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.d__12.MoveNext() Inner Exception 1: EslServerException: The remote server returned an error: (404) Not Found. HTTP GET on URI https://sandbox.e-signlive.ca/api/packages/2zfJNghK7kbSVSip_Ja5JXQ0XgE=/documents/zip. Optional details: {"messageKey":"error.validation.packageDoesNotExist","technical":"Could not retrieve the transaction summary for transaction uid: 2zfJNghK7kbSVSip_Ja5JXQ0XgE=","message":"The specified package does not exist.","code":404,"name":"Resource Not Found"} Inner Exception 2: WebException: The remote server returned an error: (404) Not Found.