Template App Data Source hard coded

I am creating a 'Template App' that connects to an Azure MS SQL database. 

I want the end users to be able to change the data source on the Template App to their own data source. 

The Template App is in pre-production so it can be shared with other organisations.

I have enabled the required options on 'control' when creating the App to allow the users to add their own data sources, 

As per Microsoft's guidance... 

'If you want to limit access to your queries and measures while still allowing your users to add their own data sources, consider checking only the Export or externally connect to data options. This enables users to add their own data sources without being able to edit your dataset'    

located here: https://docs.microsoft.com/en-us/power-bi/connect-data/service-template-apps-create 

The issue is the end user (whether from my own organisation or from a outside organisation) find the App Data Source always hard coded.  

 (server and database cannot be edited - blanked out)

Anyone?