WorkFlow Approval extension: How add WorkItemCreatedEventHandler propertie value

Hello,

In D365FO in the existing WorkFlow Approval: PurchTableApproval,

I need to fill the WorkItemCreatedEventHandler propertie with the existing PurchTableApprovalsEventHandler class value in order to

have the WorkflowWorkItemsCreatedEventHandler implements and so add the created method in the class PurchTableApprovalsEventHandler.

When i make an extension of PurchTableApproval Workflow approval object the value of the propertie WorkItemCreatedEventHandler is disabled.

And we can't add the WorkItemCreatedEventHandler implemnt keyword in the standard class PurchTableApprovalsEventHandler.

In AX2012 it was easy to do.

Is there a workaround to do this in D365FO ?

Thanks in advance