Does Microsoft.Identity.Web.TokenAcquisition support WEB APP OBO phone only auth FLOW for SQL TOKEN CACHE?

[filmong]

Does Microsoft.Identity.Web.TokenAcquisition support phone only auth with azure ad b2c where phone number is not included in claims and traditional email or upn are NOT present?

This error is happening even if the logged in user claims principal is passed in when calling Microsoft.Identity.Web.TokenAcquisition.GetAccessTokenForUserAsync.

2025-08-07 17:34:44.861 +00:00 [Debug] Microsoft.Identity.Web.TokenAcquisition: False MSAL 4.74.1.0 MSAL.NetCore .NET 8.0.16 Microsoft Windows 10.0.20348 [2025-08-07 17:34:44Z - 7ef4b3fe-0776-4d76-a79e-5bbe45ad87a8] No account passed to AcquireTokenSilent.
2025-08-07 17:34:44.868 +00:00 [Debug] Microsoft.Identity.Web.TokenAcquisition: False MSAL 4.74.1.0 MSAL.NetCore .NET 8.0.16 Microsoft Windows 10.0.20348 [2025-08-07 17:34:44Z - 7ef4b3fe-0776-4d76-a79e-5bbe45ad87a8] Token cache could not satisfy silent request.
2025-08-07 17:34:44.905 +00:00 [Error] Microsoft.Identity.Web.TokenAcquisition: False MSAL 4.74.1.0 MSAL.NetCore .NET 8.0.16 Microsoft Windows 10.0.20348 [2025-08-07 17:34:44Z - 7ef4b3fe-0776-4d76-a79e-5bbe45ad87a8] Exception type: Microsoft.Identity.Client.MsalUiRequiredException
, ErrorCode: user_null
HTTP StatusCode 0
CorrelationId 7ef4b3fe-0776-4d76-a79e-5bbe45ad87a8
To see full exception details, enable PII Logging. See https://aka.ms/msal-net-logging
at Microsoft.Identity.Client.Internal.Requests.Silent.SilentRequest.ExecuteAsync(CancellationToken cancellationToken)
at Microsoft.Identity.Client.Internal.Requests.RequestBase.<>c__DisplayClass11_1.<b__1>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.Identity.Client.Utils.StopwatchService.MeasureCodeBlockAsync(Func`1 codeBlock)
at Microsoft.Identity.Client.Internal.Requests.RequestBase.RunAsync(CancellationToken cancellationToken)

2025-08-07 17:34:44.915 +00:00 [Information] Microsoft.Identity.Web.TokenAcquisition: [MsIdWeb] An error occured during token acquisition: No account or login hint was passed to the AcquireTokenSilent call.
MSAL.NetCore.4.74.1.0.MsalUiRequiredException:

[filmong]

@RamonPage @pmaytak @keegan-caruso @jmprieur can you please point me or tag the right contact for this issue?

[filmong]

it's required to call HandleException for the server side code on MsalUiRequiredException