Solve reCAPTCHA Enterprise with C#

using System.Net.Http.Headers;
using System.Text;
using System.Text.Json.Nodes;

var key = Environment.GetEnvironmentVariable("SOLVETHREE_API_KEY")
    ?? throw new Exception("Set SOLVETHREE_API_KEY");
var proxy = Environment.GetEnvironmentVariable("SOLVETHREE_PROXY")
    ?? throw new Exception("Set SOLVETHREE_PROXY");
using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", key);
using var deadline = new CancellationTokenSource(TimeSpan.FromSeconds(180));

async Task<JsonObject> Api(HttpMethod method, string path, JsonObject? body = null)
{
    using var request = new HttpRequestMessage(method, "https://api.solvethree.com/v1" + path);
    if (body is not null)
        request.Content = new StringContent(body.ToJsonString(), Encoding.UTF8, "application/json");
    using var response = await http.SendAsync(request, deadline.Token);
    response.EnsureSuccessStatusCode();
    return JsonNode.Parse(await response.Content.ReadAsStringAsync(deadline.Token))!.AsObject();
}

var requestId = Guid.NewGuid().ToString(); // Save with these inputs for recovery.
var input = new JsonObject {
    ["site"] = "accounts.example.com", ["action"] = "login",
    ["proxy"] = proxy, ["requestId"] = requestId
};
var task = await Api(HttpMethod.Post, "/tasks?waitMs=0", input);
while (task["status"]!.GetValue<string>() is "pending" or "solving")
{
    var id = Uri.EscapeDataString(task["id"]!.GetValue<string>());
    task = await Api(HttpMethod.Get, "/tasks/" + id + "?waitMs=15000");
    if (task["status"]!.GetValue<string>() is "pending" or "solving")
        await Task.Delay(1000, deadline.Token);
}
if (task["status"]!.GetValue<string>() != "ready")
    throw new Exception("Task failed: " + task["errorCode"]?.GetValue<string>()
        + ": " + task["error"]?.GetValue<string>());
var solution = task["solution"]!.AsObject();
// Use solution["token"], ["userAgent"] and ["secChUa"] with the original proxy.
Console.WriteLine("Ready task: " + task["id"]!.GetValue<string>());