File Attachment Tool
File Attachment Tool allows you to pin the attachment to any place on a page. After choosing the File Attachment Tool you should click on the page. It opens the standard Open Files dialog box which allows you to attach PDFs and other types of files to a PDF document.
Attachments opens the Attachments pane which allows you to attach PDFs and other types of files to a PDF.
The Attachments pane has the Attachments Editor Toolbar that will allow you to open, save, add new or delete the existing files from the active document.