Purpose: Take the files created or processed by the task, and upload them to a location on the SharePoint site.
This post task action uses the Office365 credentials specified on the Server / Settings / OAuth page. If multiple credentials are defined, the system will use the credentials marked as Default unless you change to an alternate set of credentials on the Tasks / Authorization tab for this project.

Note: If you are connecting to another company's Microsft environment, you may need to make a separate set of credentials specifically authenticating against their tenant. See Here.