Embedded Multi-tenancy - Pass user to POWER for RLS

[satori-pbi]

Hi - We have an embedded application (MS sample) but now need to implement RLS.  Our application handles the end user access and authrntication.  They then arrive at the PBI Report/dashboard.  Now we need to control what they user can see but as there is only a Service Principal Profile, how can we manage RLS.  We have a database table with email and what can be accessesed but how do we combine the 2 so PBI and read the logged user.

Hope this makes sense and appreciate any ideas.