To integrate AT Internet data into Data Studio, you have to go through the AT connector. Once this connector is in place, the data that is transferred is that of your organization's Data Model.
Please note, however, that not all data is transferable. Indeed, custom metrics where an element is based on the Unique Visitor metric cannot be integrated into Google Data Studio as it is an external application.
Likewise, User Insights data can currently not be integrated into custom datasets or metrics. It is therefore not possible to integrate them into Data Studio.
This information is valid for the API v2 connector.