public override async Task OnBeforeSendAsync(HttpRequestMessage request, CancellationToken cancellationToken) { await _clientState.EnsureAuthorizedAsync(cancellationToken); request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", _clientState.AccessToken); request.Headers.Add((string)"Ocp-Apim-Subscription-Key", (string)_config.SubscriptionKey); }