PowerBI Embedded Sample Connection string

I've been testing with the PowerBI Embedded sample files.

https://azure.microsoft.com/nl-nl/documentation/articles/power-bi-embedded-get-started-sample/

Everything is working fine except a direct query report. 

There is:

Option 7: update connection string info for an existing dataset

Does anyone know what we need too fill in there?

Connection is too a SQL server with 1 DB