Hello Charlie - check out the online help about using Tableau Bridge with Tableau Online for this purpose - Web Data Connector
When you publish to Tableau Online, as a security measure, Tableau Online can't connect to or refresh an extract created by a web data connector. To refresh some web data connector extracts, you can use Tableau Bridge. For more information, see When to use Tableau Bridge to keep data fresh in the Tableau Online Help.
I will make this a seperate post.