Download Attachments is a plugin that allows you to easily add and display download links in any post or page. You upload attachment files to the Media Library directly from the page and then add either a simple Downloads panel containing all downloads attached to the page, or create individual, custom download links.
Look for the Attachments area underneath the main page details:
Click on Add new attachment, which will open up the Media Library and click on the Upload tab. You can then either drag and drop the attachment onto the page, or click and browse for the attachment file(s) you want to add:
Once added, click Add selected attachments and then the file(s) appear as below: