Using Datablending with Cube SQL API

**I want to plot two metrics that are present in separate cubes in the same chart, with SQL API**

In the docs about [Data Blending](https://cube.dev/docs/schema/advanced/data-blending) it is mentioned in the end that
"Provided we have the aforementioned tables `OnlineOrders` and `RetailOrders` let's assume that we want to chart those measures together and see how they correlate. You can simply pass the queries to the Cube.js client, and it will merge the results which will let you easily display it on the chart."

From what I understand, this is through Cube REST API. I am looking for an Cube SQL way of doing the same, as I am using superset for charting metrics