When preparing the document, you will see an Add tab in the top right.

Click on it and you will find an option below to add an Attachment or Recipient attachment.

Note: Recipient attachment is an Enterprise plus feature.

Select a file from your attachment library, upload a file, or use an external link to add it as an attachment.

Title the file or webpage and check Add to Library if you would like to have easy access to it for future docs. Decide whether you would like it to be something required for your recipient to view and then click the Add button in the bottom right.

Once you have added all of your fields and supplemental attachments, you can proceed to the Engage tab to add an introductory video or auto-comment.