Steps:

1. Log in to the System. 
2. On the main dashboard, click “Generate Documents.” You will see a list of previously generated documents.
3. Find the document you want to add supporting documents
4. Click on the Action menu at the far right and select “Document Data” this takes you a document content form
5. Select Supporting Document(s) link, then click on “Add Document” button below and fill in the relevant details on the provided form. 
6. Click on the “Select Supporting Document(s)” link, then select the “Add Document” button. 
7. A form will appear, fill in the required details accordingly.
8. After completing the form, click “Upload” to finalize the process and attach the supporting document.