SSO autentication for Edge possible?

I was searching the docs/net and just want to ensure that my understanding is correct:
If I want to use an external IdP I have to use the Backend. The backend will support Odoo or OAuth2. The Edge only supports the build in accounts guest and admin. Is that correct?
Thanks!

FYI: I was only able to get edge to work with admin, I couldnt get dummy or meta setup of creds to work. Then went through the procedure to get odoo + backend working which (after some trial and error) I discovered (since I was using docker) I needed to build a new openemsUI container with additional connectors in the build which then connected to backend. However still havn’t resolved all problems with openEMSUI container I built, i.e. some of the UI images/menu items are missing, reverts to german after restart etc
Working on other features, so was intending circle back to this later.