Non-preemptive authentication is not working with Jetty client library

Question

I am trying to do non-preemptive authentication (get 401-unauthorized with request round trip) with Jetty client. But I'm unable to get request round trip after using below code snippet.

AuthenticationStore authStore = client.getAuthenticationStore();
    if(config.getIdentityResource() != null){
        Authentication basicAuthentication = new BasicAuthentication(uri, uri+"" , (getCredentials(config))[0], getCredentials(config)[1]);

        if(config.isUseNonPreemptiveAuth())
        {
            authStore.addAuthentication(basicAuthentication); 
        }
        else if (config.isAuthEnabled() && !config.isUseNonPreemptiveAuth()) 
        {
            authStore.addAuthenticationResult(new BasicAuthentication.BasicResult(uri, (getCredentials(config))[0], getCredentials(config)[1]));
        }
}

I'm using jetty-client-9.4.51 jars. Did I miss something in the above code snippet or any Jetty specific property?

I'm expecting to see round trip request based on Jetty documentation as mentioned in text.