POSTing the JWT

gistfile1.cs

var post = new Dictionary<string, string>
{
    {"grant_type", "urn:ietf:params:oauth:grant-type:jwt-bearer"},
    {"assertion", jwt }
};

var response = _httpClientProvider.PostAsync(URI, _httpContentProvider.GetFormUrlEncodedContent(post));
var accessToken = _jsonProvider.Deserialize<AccessToken>(response);