RLS with authentication in Power BI Embedded

Hello everybody,
I was wondering how to use RLS, because I'm developing an app which displays different Power BI dashboards, because every user should have access to filtered dashboards according to their credentials.
I've read some posts about RLS, but I can't figure out if it's the right way.
I'll explain with an example:

User A authenticates via the app (with userID and Password) and then he views the dashboard with the filters automatically applied according to his permissions. Is there a way to pass the userID the user type in the login form as a parameter for filtering?

How can I implement this?
(Sorry for my bad english)