Identifying when a gateway is required
Power BI can directly connect to most cloud-based data sources. If your data source is on-premises, you will need to install and configure an on-premises data gateway. You will not need to know how to install a gateway for the exam. But you will need to know when it is necessary.
The Power BI service will inform you if a gateway is necessary. There is a Gateway connection option on the dataset settings page. If your dataset requires a gateway, this section will inform you that you have not configured your dataset to use an on-premises data gateway.
Once you add your dataset's data source to the gateway, the error will go away and you can refresh the dataset as needed.
Test Tip
You will not be able to enable the slider to schedule a refresh if a gateway is required and not set up.