Can I register Azure SQL Database with my ArcGIS E…

Can I register Azure SQL Database with my ArcGIS Enterprise Base deployment? Right now, I have a 10.9 ArcGIS Enterprise Base deployment in Azure. In the cloud builder, the option to register a database is greyed out.

Is the only option to create a federated GIS Server site and register the Azure SQL database with that? If so, does that also require an additional license on top of ArcGIS Enterprise Standard?