Power BI Push Dataset REST API - with Default Datasource

[seemasam]

Hi Team,

We are currently using the Power BI REST API calls to Push Dataset with Datasource. 
Few doubts to be clarified:

1. A datasource implementation in Push Dataset is valid only with Gateway Datasources. Is this right?
2. Is there any way for a Normal Datasource to be created using the Power BI REST API calls?
3. Can add Datasource (not under a gateway) be included in the Power BI REST API Calls?
4. Are there any mechanisms to add the datasource to a dataset, if the user uses only power bi Service?

[lbendlin]

There are no data sources for Push Datasets.  It's in the name - you push rows into that dataset, and these rows must be in (simple) JSON  format.