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.

I am testing in a site that doesnt allow open NAT ports, but successfully managed to use CloudFlare Tunnel into the site. It allows up to 100 connections per gmail account for free, which is sufficient for me to connect Backend (Ports+Felix) , multiple edge+EdgeFelix. Only thing thats a hassle was using MQTT broker on the site, si created a nginx container with MQTT read and pass through to a Rest service so could connect our DERMS+Orchestration to the site which has been working stable for 3 months now. We have a “States” engine that connects to backend + edges + the nginx container and they all use the same REST call, makes support easier when all in the one place.
/*************************************************************************
GET STATE FROM OPENEMS
*************************************************************************/
function getORCHState_JSONRPC(profile) {
var edgeIds = getEdgeIds(profile); // Pulls a list of edges
var channels = [
“_sum/EssSoc”,
“_sum/ProductionActivePower”,
“_sum/ConsumptionActivePower”,
“_sum/GridActivePower”,
“edge2evcs0/_PropertyInitialSoc”, // Still have to finish so pass evcs0 as param
“edge2evcs0/ActivePower”,
“edge2evcs0/EnergySession”,
“edge2evcs0/MaximumHardwarePower”,
“edge2evcs0/MinimumHardwarePower”,
“edge2evcs0/Status”,
“edge2ess0/AllowedDischargePower”,
“edge2ess0/AllowedChargePower” ];
var apiResult = callOpenEMS_JSONRPC(edgeIds, channels, profile);
return normalizeORCHState(profile, apiResult);}

Hope this helps ..?

Sorry, I seem to miss the relevant point here. My question was if it is possible to authenticate against the Edge (without a Backend) by an external IdP (e.g., Keycloak).
If I understand you correctly, you had to work around some network limitations and are using a Backend. I unfortunately fail to connect the dots to my question.