Test Automation Microsoft Dynamics ax 7 with Selenium

I'm working on test automation dynamics ax 7 with selenium, I followed this tutorial https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/perf-test/perfsdk-tutorial so I added the selenium reference to my project, I generated the certificate and modified in the CloudEnvironment.Config file and in wif.config. and afterwards I created the solution. and when I ran the test, these errors are displayed:

Test Name: Purchase_order_creation Test FullName: MS.Dynamics.Performance.Application.TaskRecorder.Purchase_order_creationBase.Purchase_order_creation Test Source: C:\PerfSDK\SampleProject\PerfSDKSample\Generated\Purchase_order_creationBase.cs : line 106 Test Outcome: Failed Test Duration: 0:00:00.004458

Result StackTrace: at Microsoft.IdentityModel.SecurityTokenService.X509SigningCredentials..ctor(X509SecurityToken token, SecurityKeyIdentifier ski, String signatureAlgorithm, String digestAlgorithm) at Microsoft.IdentityModel.SecurityTokenService.X509SigningCredentials..ctor(X509Certificate2 certificate) at MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.SelfMintedTokenAuthenticator.MintToken(String email, String nameId, String identityProvider, String audience, String certThumbprint, Double tokenLifetimeInHours) at MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.SelfMintedTokenAuthenticator.SignIn() at MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.AuthenticatorFactory.get_AdminAuthenticatorToken() at MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.UserManagement.get_Service() at MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.UserManagement.PopulateAxUsers() at MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.UserManagement..cctor() --- End of inner exception stack trace --- at MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.UserManagement.get_AdminUser() at MS.Dynamics.Performance.Application.TaskRecorder.Purchase_order_creationBase.TestSetup() in C:\PerfSDK\SampleProject\PerfSDKSample\Generated\Purchase_order_creationBase.cs:line 45 Result Message: Initialization method MS.Dynamics.Performance.Application.TaskRecorder.Purchase_order_creationBase.TestSetup threw exception. System.TypeInitializationException: System.TypeInitializationException: The type initializer for 'MS.Dynamics.TestTools.CloudCommonTestUtilities.Authentication.UserManagement' threw an exception. ---> System.ArgumentException: ID2057: Cannot construct a X509SigningCredentials instance for a certificate without the private key. Parameter name: token.

can you help me?