Device Code Flow causes NotImplementedException for non-Entra authorities

[girlpunk]

Library version used

4.68.0

.NET version

9.0.102

Scenario

PublicClient - desktop app

Is this a new or an existing app?

This is a new app or experiment

Issue description and reproduction steps

When following the documentation at https://learn.microsoft.com/en-us/entra/identity-platform/scenario-desktop-acquire-token-device-code-flow?tabs=dotnet to acquire an access token via device request, NotImplementedException is thrown. This appears to be coming from

microsoft-authentication-library-for-dotnet/src/client/Microsoft.Identity.Client/Instance/GenericAuthority.cs

Line 43 in 235d32d

throw new NotImplementedException();

Relevant code snippets

var Scopes = new string[] { "user.read" };

var pca = PublicClientApplicationBuilder
    .Create(ClientId)
    .WithExperimentalFeatures()
    .WithOidcAuthority(Authority)
    .WithDefaultRedirectUri()
    .Build();

pca.AcquireTokenWithDeviceCode(Scopes, deviceCodeResult =>
{
    Console.WriteLine(deviceCodeResult.Message);
    return Task.FromResult(0);
}).ExecuteAsync();

Expected behavior

A token should be retrieved, using the device code flow

Identity provider

Other

Regression

No response

Solution and workarounds

No response

[bgavrilMS]

Device code flow isn't supported for non-Entra Idenity Providers. What IdP do you use?

[girlpunk]

I'm using the Authentik. The lack of support wasn't mentioned in the documentation, is it not possible to load the relevant information from the openid-configuration endpoint? If not, could this be specified manually in the configuration?