Example of building a plotly graph from a POST request to a URL?

I want to build a plotly graph from an external datasource. I can currently fetch this data by issuing a POST request with an external URL and parameters startdate and enddate. A new record is added to this datasource every day. As I understand it, I can run a scheduled task or cron job that runs every night to fetch this new record. How do I create the plotly graph? What is it supposed to connect to? Do I have to create an independent MySQL database that fetches the new data through a cron job, or is there an easier way?