Cant get SQL queries from PBI Report Server database

Hi experts,

I am trying to find SQL queries wihch are the source of the micro data for the PBI reports storred in ReportServer database. I found this conversationWhere Can I find the published report in PowerBI Server usefull, but does not cover all my needs. 

Does anyboady know how to convert ReportServer.dbo.CatalogItemExtendedContent.Content field where ContentType='CatalogItem' to get the data source SQL queries or how to change powershell script from Anonymous  in link above to get the content of the DataMashup file from the PBI.zip file?

Thanks in advance,

Jerneja