I am attempting to use the following to determine if an Azure AD B2C logged-in user is an Administrator:
if (User.IsInRole("Administrator")) 
{
    .... Display special info for Admins ....
}
However, when I look into the System.Security.Principal.IPrincipal.User object, I see null for the list of roles that this user has:
The following is the relevant code that configures authentication and requests TokenValidationParameters, including for the roles to be validated. I've tried the following: RoleClaimType = "role" and RoleClaimType = "roles", both of which haven't worked for me.
    public void ConfigureAuth(IAppBuilder app)
    {
        app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);
        app.UseKentorOwinCookieSaver();
        app.UseCookieAuthentication(new CookieAuthenticationOptions()
        {
            CookieSecure = CookieSecureOption.Always
        });
        app.UseOpenIdConnectAuthentication(
            new OpenIdConnectAuthenticationOptions
            {
                // Generate the metadata address using the tenant and policy information
                MetadataAddress = String.Format(AadInstance, Tenant, DefaultPolicy),
                // These are standard OpenID Connect parameters, with values pulled from web.config
                ClientId = ClientId,
                Authority = Authority,
                PostLogoutRedirectUri = RedirectUri,
                RedirectUri = RedirectUri,
                Notifications = new OpenIdConnectAuthenticationNotifications()
                {
                    RedirectToIdentityProvider = OnRedirectToIdentityProvider,
                    AuthenticationFailed = OnAuthenticationFailed,
                    AuthorizationCodeReceived = OnAuthorizationCodeReceived
                },
                /////////// HERE //////////
                // Specify the claims to validate
                TokenValidationParameters = new TokenValidationParameters
                {
                    NameClaimType = "name",
                    RoleClaimType = "role",
                },
                // Specify the scope by appending all of the scopes requested into one string (seperated by a blank space)
                Scope = $"{OpenIdConnectScopes.OpenId} {ReadTasksScope} {WriteTasksScope}"
            }
        );
    }
However, when I decode the id_token retrieved from the authentication process and decode it using the tool https://jwt.ms/, I don't see a "roles" claim, as shown in the screenshot.
Furthermore, in the SignIn Azure AD B2C policy, perhaps I need to add a "roles" ClaimType?
Please help! What else do I need to do in order to get User.IsInRole("Administrator") to work? Thank you!


