ODBC Connection In Service - How To Save Username and Password

Hi, 

I am using an ODBC connection for my Power BI Reports.  I set up the System DSN and confirmed it worked on the Gateway computer. I then set up the connection in the Tenant.  My reports work fine locally when I refresh and I use the system DSN (however, it first prompted my to enter a Username and Password).  However, after the report is deployed it fails refreshing.  I believe the main issue is that it does not know what the Username and Password is. I heard you can save these setting in the registry. But, can you can save them in the connection string?  Not sure how best to resolve this. 

Cheers!