How to add attachments while cancelling of Purchase Order.

Summary:

We have some defined process for cancellation of Purchase Order. Our user needs to sign one offline PO Form and upload it to Purchase Order's attachments sections. When we try to cancel Purchase Order by using Cancel Document button, system does not provide any option to upload any attachments.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

23D

Code Snippet (add any code snippets that support your topic, if applicable):