A function to determine if report IsPublished or IsLocal

Hello,

Because I don't have access to the original data source I need an option to determine if the report is running in the Power BI service or is it local so I could change the data source depending on environment.
In this moment, the only workaround is a set of parameters (for example ServerName, DatabaseName) that have to be changed each time after I publish the report.

I have tried to set the "default value" of the parameter but will keep use the one set in the report.
I have tried to use USERNAME DAX function but this cannot be used in calculated tables or columns, and this way I should be able to detect "@" in the username because local will have the "\" symbol.

Is there a better way of changing dev/prod environments, meaning in fact local/published?

Kind Regards,
Lucian