Microsoft Power BI added a Mixpanel Connector, allowing Mixpanel data to be visualized and reported in Power BI.
We've duplicated Microsoft's support documentation below:
The Mixpanel connector can be found under the Online Services category in the Get Data dialog.
Enter your API Secret in both the API Secret and password fields for authentication
Mixpanel data is available in the form of tables or parameterized functions, ready to load into Power BI.