fix directive

Author: amalhotra-mdb

source/connect/powerbi.txt

@@ -20,7 +20,7 @@ This tutorial demonstrates how to connect to the |bi| using
 
    The MongoDB Connector does not support Direct Query in Power BI.
    However, Atlas SQL does support Direct Query in Power BI. To
-   connect to Atlas SQL from Power BI, see :ref: `sql-connect-powerbi`.
+   connect to Atlas SQL from Power BI, see :ref:`sql-connect-powerbi`.
 
 .. include:: /includes/client-connection-prereqs.rst