Unable to get Swagger UI working with Minimal API and OAuth2

I am trying to setup Auth on a new minimal API. The API needs to connect out to Graph API (using GraphServiceClient) which I have working.

I need to get security working for the API. I need to setup SwaggerUI and then look at how the client (a sharepoint client) will call the API.

I've been trying to get Swagger UI setup and when I run Swagger and click on Authorize, it opens up a second browser tab and it resolves to a redirect endpoint and just sits there spinning (status of Pending).

`oAuth2 (OAuth2, authorizationCode with PKCE) OAuth2.0 Auth Code

Authorization URL: https://login.microsoftonline.com//oauth2/v2.0/authorize

Token URL: https://login.microsoftonline.com//oauth2/v2.0/token

Flow: authorizationCode with PKCE`

I am passing the client id and secret and selecting a scope.

It redirects and I just see this

I have the following when setting up Swagger

    services.ApiRequireAuthentication()
        .AddScoped<IUserContext, JwtUserContext>()
        .AddAuthorization(options =>
        {
            options.AddPolicy(RoleNames.ApiAdminRole, policy =>
            {
                policy.AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme);
                policy.RequireRole("ApiAdmin");
            });

            options.AddPolicy(RoleNames.ApiAccessRole, policy =>
            {
                policy.AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme);
                policy.RequireRole("ApiAccess");
            });
        });

    var apiScope = azureAd?.Scopes?.Api;

    if (apiScope is null || string.IsNullOrEmpty(apiScope.Scope) || string.IsNullOrEmpty(apiScope.Description))
    {
        throw new ArgumentException("API Scope is not defined in the config.");
    }

    var authorizationUrl =  $"https://login.microsoftonline.com/{azureAd?.TenantId}/oauth2/v2.0/authorize";
    var tokenUrl = $"https://login.microsoftonline.com/{azureAd?.TenantId}/oauth2/v2.0/token";

    services.AddEndpointsApiExplorer()
        .AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new OpenApiInfo { Title = "SA DPC M365 API", Version = "v1" });
            c.AddSecurityDefinition("oAuth2", new OpenApiSecurityScheme
            {
                Type = SecuritySchemeType.OAuth2,
                Description = $"OAuth2.0 Auth Code",
                Name = "oAuth2",
                In = ParameterLocation.Header,
                Flows = new OpenApiOAuthFlows
                {                        
                    AuthorizationCode = new OpenApiOAuthFlow
                    {
                        AuthorizationUrl = new Uri(authorizationUrl),
                        TokenUrl = new Uri(tokenUrl),
                        Scopes = new Dictionary<string, string>()
                        {
                            { apiScope.Scope, apiScope.Description  }
                        }
                    }
                }
            });

        c.AddSecurityRequirement(new OpenApiSecurityRequirement()
            {
                {
                new OpenApiSecurityScheme {
                    Reference = new OpenApiReference
                    {
                        Type = ReferenceType.SecurityScheme,
                        Id = "oauth2"
                    },
                    Scheme = "oauth2",
                    Name = "oAuth2",
                    In = ParameterLocation.Header
                },
                new [] { apiScope.Scope }

                }
            });
            
        });
    }

The UI definition is

    app.UseSwagger();
    app.UseSwaggerUI(options =>
    {
        var azureSettings = configuration.GetAzureSettings();
        options.EnableTryItOutByDefault();
        options.OAuthClientId(azureSettings.ClientId);
        options.OAuthClientSecret(azureSettings?.Credentials?.ClientSecre t);
        options.OAuthUsePkce();
       options.OAuthScopeSeparator(" ");
    });