Could you please post screenshot of your scenario? Do you install personal gateway or on-premises gateway? Currently, connecting to PostgreSQL data Source with on-premises gateway is not supported, please vote this idea to help Power BI team prioritize this feature.
If you install personal gateway, please configure the personal gateway following the instructions in this similar blog, once you properly configure personal gateway, you are able to sign in data source and set schedule refresh in the dataset’s Settings screens.
Thanks, Lydia Zhang
Community Support Team _ Lydia Zhang If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.