Polly AuthRefresh

Policy.cs

var authorisationEnsuringPolicy = Policy
    .HandleResult<HttpResponseMessage>(r => r.StatusCode == HttpStatusCode.Unauthorized) 
    .RetryAsync(
       retryCount: 1, // Consider how many retries. If auth lapses and you have valid credentials, one should be enough; too many tries can cause some auth systems to blacklist. 
       onRetryAsync: async (outcome, retryNumber, context) => FooRefreshAuthorizationAsync(context), 
      /* more configuration */); 

var response = authorisationEnsuringPolicy.ExecuteAsync(context => DoSomethingThatRequiresAuthorization(context), cancellationToken);