Не документированное Api Abcex. парсинг валюты USDT/ RUB

ApiAbcex.cs

public class ApiAbcex
{
    private static string AbcexToken = "";
    public static async Task<double> GetCurrentRateFiat()
    {
        var @return = string.Empty;

        var response = await CustomHttpGetResponseAsync(AbcexToken);

        if (response.StatusCode == HttpStatusCode.Unauthorized)
        {
            var tokenResponse = await GetToken();
            var jsonTokens = await tokenResponse.Content.ReadAsStringAsync();
            JObject responseObject = JObject.Parse(jsonTokens);
            string token = responseObject["token"]?.ToString();
            AbcexToken = token;
            await GetCurrentRateFiat();
            return 0;
        }

        var json = await response.Content.ReadAsStringAsync();

        JArray dataArray = JArray.Parse(json);

        foreach (var item in dataArray)
        {
            string marketId = item["marketId"]?.ToString();
            string price = item["price"]?.ToString();

            if (marketId == "USDTRUB")
                @return = price;
        }

        return double.Parse(@return);
    }

    private static async Task<HttpResponseMessage> CustomHttpGetResponseAsync(string token)
    {
        using (HttpClient httpClient = new HttpClient())
        {
            httpClient.BaseAddress = new Uri("https://m.abcex.io/api/v1/markets/price-dynamics?lang=ru");

            httpClient.DefaultRequestHeaders.Authorization =
                new AuthenticationHeaderValue("Bearer", token);

            var response = await httpClient.GetAsync(httpClient.BaseAddress);

            return response;
        }
    }

    public static async Task<HttpResponseMessage> GetToken()
    {
        using (HttpClient httpClient = new HttpClient())
        {
            httpClient.BaseAddress = new Uri("https://m.abcex.io/api/v1/auth/login?lang=ru");

            var Data = new
            {
                username = "You login",
                password = "You password",
                auth2fa_code = "2666"
            };

            var json = JsonConvert.SerializeObject(Data);
            var content = new StringContent(json, Encoding.UTF8, "application/json");

            var response = await httpClient.PostAsync(httpClient.BaseAddress, content);

            return response;
        }
    }
}