The primary role of gateway administrators is to add data sources per the gateway cluster and to authorize (or remove) users or groups of users. With the gateway cluster selected within the Manage gateways portal, clicking ADD DATA SOURCE from the list of gateway clusters creates a blank new data source, as shown in the following image:

New data sources can also be added via the ellipsis to the right of each cluster name in the Manage gateways portal. Once data sources have been added, the users who will publish reports and/or schedule data refreshes via the gateway can be added to the data source.

In the following example, a security group of users is added to the AdWorksDW data source of the Frontline Gateway:

The users included in the security group (for example, AdWorks DW Sales Team) will see the option to use the Frontline Gateway to configure scheduled refreshes in the Data Source Settings menu. For DirectQuery datasets and Live connections to on-premises SSAS databases, Power BI Desktop will advise that a gateway has been applied when the PBIX file is published.