azure active directory – User not allowed by policy conditions – Entra External ID for customers

I am using External ID for my customer tenant, authenticating via an Angular SPA.

My setup is identical to what is described in this article: learn.microsoft.com/en-us/entra/external-id/customers/sample-single-page-app-angular-sign-in

I downloaded the sample app provided by Microsoft, replaced the auth config my details and attempted to login with a personal email account. I am able to create a new account inside the tenant but when the app attempts to retrieve a token the following error is returned.

{
    "error": "invalid_grant",
    "error_description": "AADSTS131010: User not allowed by policy conditions. Trace ID: b989b1cf-f73e-4d3e-b23e-a35907f50000 Correlation ID: 11dee46b-a316-4265-9a90-5810cd78f395 Timestamp: 2024-01-23 01:50:02Z",
    "error_codes": [
        131010
    ],
    "timestamp": "2024-01-23 01:50:02Z",
    "trace_id": "b989b1cf-f73e-4d3e-b23e-a35907f50000",
    "correlation_id": "11dee46b-a316-4265-9a90-5810cd78f395",
    "suberror": "bad_token"
}

I can also see the failed request in Entra. Not what to do at this point other than start from scratch and see if that resolves the issue. Any thoughts?