You can use the Document Editor to add pages to an existing document, making it easy to combine multiple documents into a single file.
Note: The Document Editor is available only to SOLO and TEAMS accounts. It can only be used within the in-bundle Document Editor and is not available when editing the full bundle PDF.
First, right click on an individual document in your bundle and select "Edit" to open the document in the PDF editor.
You can then select the "Document Editor" tool in the toolbar.
This will open a panel showing the thumbnails of each page in the document. To add pages click the "New Page" button to add a blank page - alternatively, you can click "Import Document" to merge this document with another PDF.
You can then click and drag the page thumbnails while in the "Document Editor" tool to move the page locations. After making any changes, click the "Save" button to save.