HttpClientAllocations.cs

var invoker = new HttpMessageInvoker(new SocketsHttpHandler
{
    UseCookies = false,
    UseProxy = false,
    ActivityHeadersPropagator = null,
    AllowAutoRedirect = false,
    AutomaticDecompression = System.Net.DecompressionMethods.None,
    PooledConnectionIdleTimeout = TimeSpan.FromDays(1)
});

var uri = new Uri("http://httpbin.org/get");

for (int repeat = 0; repeat < 4; repeat++)
{
    if (repeat != 0)
    {
        Console.WriteLine("Pausing");
        await Task.Delay(1000);
    }

    for (int i = 0; i < 10; i++)
    {
        var request = new HttpRequestMessage(HttpMethod.Get, uri);
        request.Headers.TryAddWithoutValidation("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8");
        request.Headers.TryAddWithoutValidation("Accept-Encoding", "gzip, deflate");
        request.Headers.TryAddWithoutValidation("Accept-Language", "en-GB,en-US;q=0.9,en;q=0.8,cs;q=0.7");
        request.Headers.TryAddWithoutValidation("Cache-Control", "max-age=0");
        request.Headers.TryAddWithoutValidation("Connection", "keep-alive");
        request.Headers.TryAddWithoutValidation("Host", "httpbin.org");
        request.Headers.TryAddWithoutValidation("Upgrade-Insecure-Requests", "1");
        request.Headers.TryAddWithoutValidation("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36");

        using HttpResponseMessage response = await invoker.SendAsync(request, CancellationToken.None);

        await response.Content.CopyToAsync(Stream.Null);
    }
}