Get user access to warehouse in SQL Server without a workspace membership

Hi Community,

In Power BI Fabric, how are you getting access for a Pro license user to the warehouse in SQL Server without giving them workspace membership? I tried the solution by Adam of Guy in a Cube, but https://youtu.be/MdmPjZAV9I8?si=V5b6Dd_aXE0WptzK&t=476 . But where Jane Doe can log into SQL at 8:49 in the video, I get the error: 

Login failed for user '<token-identified principal>'. (Framework Microsoft SqlClient Data Provider)'

------------------------------

Error Number: 18456

Severity: 14

State: 198

Line Number: 65536

Any ideas or workarounds?

Thanks!