private void AddAuthorizationHeaders(string phone, string code)
{
const string authHeaderName = "Authorization";
const string deviceIdHeaderName = "device-id";
const string deviceOsHeaderName = "device-os";
var credentionalBuffer = new UTF8Encoding().GetBytes($"{phone}:{code}");
_client.AddDefaultHeaders(new Dictionary <string, string>
{
{ authHeaderName, $"Basic {Convert.ToBase64String(credentionalBuffer)}" },
{ deviceIdHeaderName, "" },
{ deviceOsHeaderName, "" }
});
}