How do I attach a document to a Broadcast Message?

Each Broadcast Message message may have up to three files attached to it.

Navigate to the “Broadcast Main” page by clicking the “Broadcast” tab.
Click "Create New Message" or open a saved message draft.
When you're ready to attach a file, click "Add attachment(s)" in the right-hand panel:
You'll be prompted to select from previously-attached files, or upload a new file.
When a file is successfully attached, it will be displayed in the Attachments section in the right-hand panel. You may remove a file attachment by clicking the red “X” icon.