Embedded Power BI - Dynamic RLS without using active directory

[boredAI]

Hi, I am working for a SAAS provider looking at implementing Power BI as an embedded BI solution.

Context: We have many clients with many users with different data access rules. The users data permissions are all defined in a security data table by the users ID for dynamic RLS. The client's users do not have microsoft active directory accounts on our servers. What we need to do is call power bi embedded to filter based on the user id passed from the website. We know the normal way to do this is to use AD to do the dynamic RLS in  power bi, but we don’t want to create 10,000 AD accounts just to do the filtering.

Main Question: When a user logs into our website and it calls the embedded power bi solution. How can we filter their power BI dashboard down to RLS without using Active directory.